Difference between revisions of "Saccharomyces"

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''Saccharomyces cerevisiae'' var. ''diastaticus'' is a variant of ''S. cerevisiae'' that can ferment certain types of starches and dextrins, and has been identified as a contaminant in breweries and is responsible for a few large recalls.  Although these strains do not produce flavors that are considered unpleasant, it is often viewed as a contaminant because of its ability to over-attenuate.  A survey of contamination reports in the last ten years at European breweries (50% of which were German breweries, which are obligated by law to report such contaminations) found an increase in reports from 2015, 2016, and 2017. 71% of the contamination incidents originated from the packaging systems (bottling/canning lines).  These contaminations were tracked down to the filler environment and/or biofilms in the pipework system of the filler which stemmed from hygienic problems.  As such, sometimes contaminations can be sporadic with some bottles being contaminated while others are not.  The other 29% of the contaminations were tracked down to primary contaminations in the brewhouse, fermentation cellar, and storage cellar  <ref name="Meier-Dörnberg">[https://www.mbaa.com/publications/tq/tqPastIssues/2017/Pages/TQ-54-4-1130-01.aspx Incidence of Saccharomyces cerevisiae var. diastaticus in the Beverage Industry: Cases of Contamination, 2008–2017.  Tim Meier-Dörnberg, Fritz Jacob, Maximilian Michel, and Mathias Hutzler.  2017.  MBAA Technical Quarterly; http://dx.doi.org/10.1094/TQ-54-4-1130-01.]</ref>.     
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''Saccharomyces cerevisiae'' var. ''diastaticus'' is a variant of ''S. cerevisiae'' that can ferment certain types of starches and dextrins, and has been identified as a contaminant in breweries and is responsible for a few large recalls.  Although these strains do not produce flavors that are considered unpleasant (although all ''diastaticus'' strains tested in one study produced phenols <ref name="Meier-Dörnberg_2018">[https://www.ncbi.nlm.nih.gov/pubmed/29518233 Saccharomyces cerevisiae variety diastaticus friend or foe? Spoilage potential and brewing ability of different Saccharomyces cerevisiae variety diastaticus yeast isolates by genetic, phenotypic and physiological characterization.  Meier-Dörnberg T, Kory OI, Jacob F, Michel M, Hutzler M.  2018.  doi: 10.1093/femsyr/foy023.]</ref>), it is often viewed as a contaminant because of its ability to over-attenuate.  A survey of contamination reports in the last ten years at European breweries (50% of which were German breweries, which are obligated by law to report such contaminations) found an increase in reports from 2015, 2016, and 2017. 71% of the contamination incidents originated from the packaging systems (bottling/canning lines).  These contaminations were tracked down to the filler environment and/or biofilms in the pipework system of the filler which stemmed from hygienic problems.  As such, sometimes contaminations can be sporadic with some bottles being contaminated while others are not.  The other 29% of the contaminations were tracked down to primary contaminations in the brewhouse, fermentation cellar, and storage cellar  <ref name="Meier-Dörnberg">[https://www.mbaa.com/publications/tq/tqPastIssues/2017/Pages/TQ-54-4-1130-01.aspx Incidence of Saccharomyces cerevisiae var. diastaticus in the Beverage Industry: Cases of Contamination, 2008–2017.  Tim Meier-Dörnberg, Fritz Jacob, Maximilian Michel, and Mathias Hutzler.  2017.  MBAA Technical Quarterly; http://dx.doi.org/10.1094/TQ-54-4-1130-01.]</ref>.     
  
 
This variant of ''S. cerevisiae'' can produce extracellular glucoamylase (also called [https://en.wikipedia.org/wiki/Alpha-glucosidase alpha-glucosidase], which is the same enzyme that ''[[Brettanomyces]]'' produces to break down starches and dextrins).  This enzyme is released outside of the cell and can break down the α-1,4 linkages of starches and dextrins releasing glucose that is then fermented by the yeast.  The capability to produce this enzyme is encoded by the STA1, STA2, or STA3 genes.  Not all strains containing one of these genes produces the glucoamylase enzyme, or are as effective as others at metabolizing dextrins <ref>[https://link.springer.com/article/10.1007%2FBF00365634 STA10: A gene involved in the control of starch utilization by Saccharomyces. Julio Polaina, Melanie Y. Wiggs.  1983.]]</ref><ref>[http://onlinelibrary.wiley.com/doi/10.1002/yea.1102/full Structural analysis of glucoamylase encoded by the STA1 gene of Saccharomyces cerevisiae (var. diastaticus).  Ana Cristina Adam, Lorena Latorre-Garcia, Julio Polaina.  2004.]</ref>.  However, it has been reported by some microbiologists that most (if not all) brewing strains that contain STA1, STA2, or STA3 do produce the glucoamylase enzyme <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1935201836508021/?comment_id=1936604203034451&reply_comment_id=1937166892978182&comment_tracking=%7B%22tn%22%3A%22R7%22%7D Richard Preiss.  Milk the Funk thread about STA1 gene correlation to glucoamylase production.  12/31/2017.]</ref><ref name="mbaa_diastaticus">[http://masterbrewerspodcast.com/068-diastaticus-part-1 Matthew Peetz of Inland Island and Tobias Fischborn of Lallemand.  "Master Brewers Association Podcast"  12/25/2017.]</ref>(~16 mins).  When beer containing this yeast is packaged too early, it will continue to slowly ferment dextrins and cause over-carbonation.  When pitching a proper cell count or pitching rate of a ''diastaticus'' yeast strain into the wort, it will fully ferment as quickly or nearly as quickly as any other brewers yeast.  ''S. cerevisiae'' var ''diastaticus'' can grow at 37°C and can also remain viable at refrigeration temperatures <ref>[http://www.ebc2017.com/inhalt/uploads/P095_Begrow.pdf Wade Begrow.  "Recent notable microbiological contaminations of craft beer in the United States".  Presentation poster at EBC 2017.  Retrieved 11/19/2017.]</ref>.  These strains are effectively eliminated by standard cleaning and sanitation practices, although inadequate cleaning hygiene can lead to biofilm formation which makes them more resistant to cleaning regiments <ref name="Meier-Dörnberg" />.  The problem of slow fermentation in already packaged beer is only a concern when ''diastaticus'' is introduced as a very small cell count, for example as an accidental contamination <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1982499288444942/?comment_id=1983013578393513&comment_tracking=%7B%22tn%22%3A%22R1%22%7D Caroline Whalen Taggart.  Milk The Facebook post on how quickly diastaticus ferments.  02/09/2018.]</ref>.  The enzyme produced by these strains is heat stable and can continue to work on starches and dextrins even after the yeast is killed by heat pasteurization <ref>[https://www.mbaa.com/publications/tq/tqPastIssues/1983/Abstracts/tq83ab19.htm Factors That Control the Utilization Of Wort Carbohydrates by Yeast.  G. G. Stewart, I. Russell, and A. M. Sills.  MBAA Technical Quarterly, Vol. 20, No. 1, 1983.] </ref>.   
 
This variant of ''S. cerevisiae'' can produce extracellular glucoamylase (also called [https://en.wikipedia.org/wiki/Alpha-glucosidase alpha-glucosidase], which is the same enzyme that ''[[Brettanomyces]]'' produces to break down starches and dextrins).  This enzyme is released outside of the cell and can break down the α-1,4 linkages of starches and dextrins releasing glucose that is then fermented by the yeast.  The capability to produce this enzyme is encoded by the STA1, STA2, or STA3 genes.  Not all strains containing one of these genes produces the glucoamylase enzyme, or are as effective as others at metabolizing dextrins <ref>[https://link.springer.com/article/10.1007%2FBF00365634 STA10: A gene involved in the control of starch utilization by Saccharomyces. Julio Polaina, Melanie Y. Wiggs.  1983.]]</ref><ref>[http://onlinelibrary.wiley.com/doi/10.1002/yea.1102/full Structural analysis of glucoamylase encoded by the STA1 gene of Saccharomyces cerevisiae (var. diastaticus).  Ana Cristina Adam, Lorena Latorre-Garcia, Julio Polaina.  2004.]</ref>.  However, it has been reported by some microbiologists that most (if not all) brewing strains that contain STA1, STA2, or STA3 do produce the glucoamylase enzyme <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1935201836508021/?comment_id=1936604203034451&reply_comment_id=1937166892978182&comment_tracking=%7B%22tn%22%3A%22R7%22%7D Richard Preiss.  Milk the Funk thread about STA1 gene correlation to glucoamylase production.  12/31/2017.]</ref><ref name="mbaa_diastaticus">[http://masterbrewerspodcast.com/068-diastaticus-part-1 Matthew Peetz of Inland Island and Tobias Fischborn of Lallemand.  "Master Brewers Association Podcast"  12/25/2017.]</ref>(~16 mins).  When beer containing this yeast is packaged too early, it will continue to slowly ferment dextrins and cause over-carbonation.  When pitching a proper cell count or pitching rate of a ''diastaticus'' yeast strain into the wort, it will fully ferment as quickly or nearly as quickly as any other brewers yeast.  ''S. cerevisiae'' var ''diastaticus'' can grow at 37°C and can also remain viable at refrigeration temperatures <ref>[http://www.ebc2017.com/inhalt/uploads/P095_Begrow.pdf Wade Begrow.  "Recent notable microbiological contaminations of craft beer in the United States".  Presentation poster at EBC 2017.  Retrieved 11/19/2017.]</ref>.  These strains are effectively eliminated by standard cleaning and sanitation practices, although inadequate cleaning hygiene can lead to biofilm formation which makes them more resistant to cleaning regiments <ref name="Meier-Dörnberg" />.  The problem of slow fermentation in already packaged beer is only a concern when ''diastaticus'' is introduced as a very small cell count, for example as an accidental contamination <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1982499288444942/?comment_id=1983013578393513&comment_tracking=%7B%22tn%22%3A%22R1%22%7D Caroline Whalen Taggart.  Milk The Facebook post on how quickly diastaticus ferments.  02/09/2018.]</ref>.  The enzyme produced by these strains is heat stable and can continue to work on starches and dextrins even after the yeast is killed by heat pasteurization <ref>[https://www.mbaa.com/publications/tq/tqPastIssues/1983/Abstracts/tq83ab19.htm Factors That Control the Utilization Of Wort Carbohydrates by Yeast.  G. G. Stewart, I. Russell, and A. M. Sills.  MBAA Technical Quarterly, Vol. 20, No. 1, 1983.] </ref>.   
  
Var. ''diastaticus'' contamination in breweries has been a recent hot topic, and the source of some contaminations has been suspected to come from certain yeast suppliers (namely White Labs) <ref>[https://www.courthousenews.com/wp-content/uploads/2017/11/Left-Hand-v-White-Labs-COMPLAINT.pdf District Court, Boulder County, Colorado.  Case Number 2017CV31132.  Filed 11/14/2017.]</ref>.  Detection of ''S. cerevisiae'' var. ''diastaticus'' as a contaminant can be difficult.  Contamination usually occurs as a secondary contaminant (meaning in the packaging system), and can come from contact with beer lines, by air circulation in the area of the packaging equipment, or by insufficient heat treatment of the packaging line.  Since a very small number of cells is enough to contaminate beer, contaminations can be sporadic with only a percentage of bottles being contaminated <ref name="Meier-Dörnberg_2018">[https://www.ncbi.nlm.nih.gov/pubmed/29518233 Saccharomyces cerevisiae variety diastaticus friend or foe? Spoilage potential and brewing ability of different Saccharomyces cerevisiae variety diastaticus yeast isolates by genetic, phenotypic and physiological characterization.  Meier-Dörnberg T, Kory OI, Jacob F, Michel M, Hutzler M.  2018.  doi: 10.1093/femsyr/foy023.]</ref>.  Documented attenuation percentages above 75% for any strain of ''S. cerevisiae'' is also an indicator that the strain could be ''diastaticus'', however, some non-diastaticus strains can also attenuate higher than 75%, so this indicator is not a reliable method to be sure that a given strain is ''diastaticus'' <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2004689559559248/?comment_id=2004695002892037&reply_comment_id=2005133672848170&comment_tracking=%7B%22tn%22%3A%22R1%22%7D Adi Hastings.  Milk The Funk Facebook Group post on non-diastaticus strains with high attenuation.  02/27/2018.]</ref><ref name="mbaa_diastaticus" />.  Often this contamination can only be detected by sensory testing weeks after packaging.  This yeast has reportedly been detected using [http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1981.tb04005.x/pdf LCSM agar plates], although other species of wild ''Saccharomyces'' yeast can grow on this media <ref name="mbaa_diastaticus" />(~18 mins) and PCR DNA analysis is required to give a positive identification of ''diastaticus''.  Cheaper methods of doing PCR are recently becoming available, and could help breweries with smaller budgets sufficiently detect this as a contaminant (see [[Laboratory_Techniques#PCR.2FqPCR|PCR Lab Techniques]]).
+
Var. ''diastaticus'' contamination in breweries has been a recent hot topic, and the source of some contaminations has been suspected to come from certain yeast suppliers (namely White Labs) <ref>[https://www.courthousenews.com/wp-content/uploads/2017/11/Left-Hand-v-White-Labs-COMPLAINT.pdf District Court, Boulder County, Colorado.  Case Number 2017CV31132.  Filed 11/14/2017.]</ref>.  Detection of ''S. cerevisiae'' var. ''diastaticus'' as a contaminant can be difficult.  Contamination usually occurs as a secondary contaminant (meaning in the packaging system), and can come from contact with beer lines, by air circulation in the area of the packaging equipment, or by insufficient heat treatment of the packaging line.  Since a very small number of cells is enough to contaminate beer, contaminations can be sporadic with only a percentage of bottles being contaminated <ref name="Meier-Dörnberg_2018" />.  Documented attenuation percentages above 75% for any strain of ''S. cerevisiae'' is also an indicator that the strain could be ''diastaticus'', however, some non-diastaticus strains can also attenuate higher than 75%, so this indicator is not a reliable method to be sure that a given strain is ''diastaticus'' <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2004689559559248/?comment_id=2004695002892037&reply_comment_id=2005133672848170&comment_tracking=%7B%22tn%22%3A%22R1%22%7D Adi Hastings.  Milk The Funk Facebook Group post on non-diastaticus strains with high attenuation.  02/27/2018.]</ref><ref name="mbaa_diastaticus" />.  Often this contamination can only be detected by sensory testing weeks after packaging.  This yeast has reportedly been detected using [http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1981.tb04005.x/pdf LCSM agar plates], although other species of wild ''Saccharomyces'' yeast can grow on this media <ref name="mbaa_diastaticus" />(~18 mins) and PCR DNA analysis is required to give a positive identification of ''diastaticus''.  Cheaper methods of doing PCR are recently becoming available, and could help breweries with smaller budgets sufficiently detect this as a contaminant (see [[Laboratory_Techniques#PCR.2FqPCR|PCR Lab Techniques]]).
  
 
WY3711 saison yeast, which originated from Basserie Thiriez, has been determined to be this subspecies <ref name="preiss_diastaticus" />.  In the [[Saccharomyces#Commercial_Farmhouse.2FBelgian_Strains_of_Saccharomyces|commercial culture]] lists below where we believe a lab is selling this strain of yeast or might be selling this strain of yeast, we note that it is determined/suspected to be ''diastaticus''.  The Belle Saison strain from Lallemand is killer neutral, which means that killer wine strains will not kill it (it is not verified if Belle Saison is the same as WY3711/Thiriez, although it is suspected to be).
 
WY3711 saison yeast, which originated from Basserie Thiriez, has been determined to be this subspecies <ref name="preiss_diastaticus" />.  In the [[Saccharomyces#Commercial_Farmhouse.2FBelgian_Strains_of_Saccharomyces|commercial culture]] lists below where we believe a lab is selling this strain of yeast or might be selling this strain of yeast, we note that it is determined/suspected to be ''diastaticus''.  The Belle Saison strain from Lallemand is killer neutral, which means that killer wine strains will not kill it (it is not verified if Belle Saison is the same as WY3711/Thiriez, although it is suspected to be).

Revision as of 10:58, 23 March 2018

Saccharomyces is considered a yeast, although this term is historical and ill-defined. Saccharomyces is a genus of fungus including many species. The distinct species of Saccharomyces are revised frequently as more research is done. All species are unicellular and capable of fermentation. Saccharomyces cerevisiae is the most well-known species of yeast. It is used in the fermentation of beer, wine, and sake, and as a leavening agent in bread. It is commonly referred to as "ale yeast", "wine yeast" (see Killer Wine Yeast below), or "bread yeast". S. pastorianus, known as lager yeast, is a hybrid closely related to S. cerevisiae but is not a true species. S. cerevisiae is commonly studied as a model organism and was the first eukaryote to have its genome entirely sequenced. In rare cases, Saccharomyces can form a pellicle.

See Lactobacillus, Pediococcus, Brettanomyces, Mixed Cultures, and Nonconventional Yeasts and Bacteria charts for other commercially available cultures.

Species

Saccharomyces cerevisiae is the type species of the genus Saccharomyces, although Saccharomyces paradoxus, S. cerevisiae's closest relative, is likely older and more globally ubiquitous than S. cerevisiae. [1] Many previously recognised species of Saccharomyces have been consolidated or reassigned to another genus, commonly Zygosaccharomyces.

Species Ecology Notes
S. cerevisiae Domestic: Beer, Wine, Bread. Wild: Ripe fruits. Believed to have been originally isolated from the skin of grapes
S. paradoxus Deciduous trees (oak, maple, birch) Closest known species to the baker's yeast
S. eubayanus Patagonia Probable parent of lager yeast
S. mikatae Decayed leaves in Japan Example
S. kudriavzevii Decayed leaves in Japan Example
S. bayanus Wine Possible hybrid of S. eubayanus and S. cerevisiae. Possible parent of S. pastorianus.
S. florentinus Drosophila and sulphurized grape must Example
Example Example Example

S. cerevisiae

Native Environment

Although it has been long understood that S. cerevisiae occurs naturally on bark and fruit, recent studies suggest that some Saccharomyces species are more abundant in leaf matter on the ground. See the "Where (Do) the Wild Yeast Roam" video by Bryan from Sui Generis blog and these studies/discussions:

History of Domestication

Killer Wine Yeast

Many wine yeast strains are known to be "killer" yeast strains (this term has been changed to "zymocidal" in science [2]). In Saccharomyces, killer strains are genetically determined to secrete toxins (in the form of extracellular proteins or glycoproteins) called 'mycocins' that kill sensitive strains. The mycocin toxins can act on sensitive strains in a number of ways: by blocking DNA synthesis and preventing cell division, inhibiting the synthesis of beta-glucans (β-1,6-glucan) that a part of their cell wall formation, and by causing ions to leak through the cell wall. In low dosages, which is typical in the natural environment, toxin triggers active cell death (apoptosis), while large dosages cause necrotic cell killing (necrosis). One study in wine found that the use of killer strains to out compete sensitive strains resulted in off-flavors from yeast autolysis [3][4]. Another study found that a lager strain that was genetically modified to secrete killer toxins was able to eliminate all cells of a sensitive ale strain within 24 hours of beer fermentation at a pitching rate of 99% sensitive ale strain to 1% killer lager strain, indicating that even a small amount of killer cells is enough to kill a larger population of sensitive cells [2]. Neutral strains do not produce toxins, nor are they killed by them [5]. Almost all ale and lager strains are sensitive to the toxins produced by killer strains [6][7].

In Saccharomyces, four toxins have been identified: K1, K2, K28, and Klus, the first three of which can only kill other strains/species of Saccharomyces. The Klus toxin has been found to kill all strains of S. cerevisiae (including those that produce the previous three toxins), as well as yeast from other genera, such as Hanseniaspora spp., Kluyveromyces lactis, Candida albicans, Candida dubliniensis, Candida kefir and Candida tropicalis [8]. However, none of the toxins secreted by killer strains of Saccharomyces have been found to kill Brettanomyces [9]. The K1 toxin is most active between a pH of 4.6 and 4.8, while K2 and Klus are active around a pH of 4.0 to 4.3 [8]. The activity of the toxin is greatest during the log phase of growth, and decays during the stationary phase of fermentation [10].

Various other yeast species have the ability to produce toxins that effect a range of other yeasts and bacteria, including species from the genera Candida, Cryptococcus, Debaryomyces, Hanseniaspora, Hansenula, Kluyveromyces, Metschnikowia, Pichia, Ustilago, Torulopsis, Williopsis, Zygosaccharomyces, Aureobasidium, Zygowilliopsis, and Mrakia [10][2]. For example, strains of the yeast species Candida pyralidae [10], Wickerhamomyces anomalus, Kluyveromyces wickeramii, Torulaspora delbrueckii and Pichia membranifaciens have been found to produce toxin that inhibits Brettanomyces [11]. In addition, the toxin produced by Wickerhamomyces anomalus and Williopsis markii have been found to inhibit a wide range of spoilage and pathogenic fungi [4]. Killer strains of S. cerevisiae and other yeast can occur naturally in the wild on fruit and can have a negative impact on other flora that are found in the same environment [10]. Strains of Torulaspora delbrueckii have been shown to kill killer strains of S. cerevisae (wine strains), as well as to kill Pichia species [11].

Saccharomyces cerevisiae var. diastaticus

Do a page search (CTRL+F) on this wiki page for the term "diastaticus" to see all of the confirmed or suspected diasaticus strains listed in the commercial culture charts below.

Saccharomyces cerevisiae var. diastaticus is a variant of S. cerevisiae that can ferment certain types of starches and dextrins, and has been identified as a contaminant in breweries and is responsible for a few large recalls. Although these strains do not produce flavors that are considered unpleasant (although all diastaticus strains tested in one study produced phenols [12]), it is often viewed as a contaminant because of its ability to over-attenuate. A survey of contamination reports in the last ten years at European breweries (50% of which were German breweries, which are obligated by law to report such contaminations) found an increase in reports from 2015, 2016, and 2017. 71% of the contamination incidents originated from the packaging systems (bottling/canning lines). These contaminations were tracked down to the filler environment and/or biofilms in the pipework system of the filler which stemmed from hygienic problems. As such, sometimes contaminations can be sporadic with some bottles being contaminated while others are not. The other 29% of the contaminations were tracked down to primary contaminations in the brewhouse, fermentation cellar, and storage cellar [13].

This variant of S. cerevisiae can produce extracellular glucoamylase (also called alpha-glucosidase, which is the same enzyme that Brettanomyces produces to break down starches and dextrins). This enzyme is released outside of the cell and can break down the α-1,4 linkages of starches and dextrins releasing glucose that is then fermented by the yeast. The capability to produce this enzyme is encoded by the STA1, STA2, or STA3 genes. Not all strains containing one of these genes produces the glucoamylase enzyme, or are as effective as others at metabolizing dextrins [14][15]. However, it has been reported by some microbiologists that most (if not all) brewing strains that contain STA1, STA2, or STA3 do produce the glucoamylase enzyme [16][17](~16 mins). When beer containing this yeast is packaged too early, it will continue to slowly ferment dextrins and cause over-carbonation. When pitching a proper cell count or pitching rate of a diastaticus yeast strain into the wort, it will fully ferment as quickly or nearly as quickly as any other brewers yeast. S. cerevisiae var diastaticus can grow at 37°C and can also remain viable at refrigeration temperatures [18]. These strains are effectively eliminated by standard cleaning and sanitation practices, although inadequate cleaning hygiene can lead to biofilm formation which makes them more resistant to cleaning regiments [13]. The problem of slow fermentation in already packaged beer is only a concern when diastaticus is introduced as a very small cell count, for example as an accidental contamination [19]. The enzyme produced by these strains is heat stable and can continue to work on starches and dextrins even after the yeast is killed by heat pasteurization [20].

Var. diastaticus contamination in breweries has been a recent hot topic, and the source of some contaminations has been suspected to come from certain yeast suppliers (namely White Labs) [21]. Detection of S. cerevisiae var. diastaticus as a contaminant can be difficult. Contamination usually occurs as a secondary contaminant (meaning in the packaging system), and can come from contact with beer lines, by air circulation in the area of the packaging equipment, or by insufficient heat treatment of the packaging line. Since a very small number of cells is enough to contaminate beer, contaminations can be sporadic with only a percentage of bottles being contaminated [12]. Documented attenuation percentages above 75% for any strain of S. cerevisiae is also an indicator that the strain could be diastaticus, however, some non-diastaticus strains can also attenuate higher than 75%, so this indicator is not a reliable method to be sure that a given strain is diastaticus [22][17]. Often this contamination can only be detected by sensory testing weeks after packaging. This yeast has reportedly been detected using LCSM agar plates, although other species of wild Saccharomyces yeast can grow on this media [17](~18 mins) and PCR DNA analysis is required to give a positive identification of diastaticus. Cheaper methods of doing PCR are recently becoming available, and could help breweries with smaller budgets sufficiently detect this as a contaminant (see PCR Lab Techniques).

WY3711 saison yeast, which originated from Basserie Thiriez, has been determined to be this subspecies [23]. In the commercial culture lists below where we believe a lab is selling this strain of yeast or might be selling this strain of yeast, we note that it is determined/suspected to be diastaticus. The Belle Saison strain from Lallemand is killer neutral, which means that killer wine strains will not kill it (it is not verified if Belle Saison is the same as WY3711/Thiriez, although it is suspected to be).

White Labs now reports that the strains WLP590, WLP099, WLP045, WLP570, and WLP644 are diastaticus. Some hints as to which other White Labs products might be diastaticus have been deduced from the Gallone et al. study that published DNA sequencing on most of the yeast strains in the White Labs bank. However, the codes used in the Gallone paper for each strain of yeast were not defined as far as which White Labs products correspond to which code used in the study. Some of the codes have been speculated on which White Labs strains they might refer to (see History of Domestication above). The strains from the Gallone paper that appear to contain STA1 are Beer002, Wine019, Beer092 and Beer059. The Beer059 code might correspond to WLP026 according to this speculative table, which has had reports of high attenuation. It is not clear at this time whether this strain is diastaticus or not [24]. There has been a report by Richard Preiss of Escarpment Laboratories that WLP570 and WLP585 both have the STA1 gene, but it takes weeks before they hyper-attenuate [25]. Other yeast labs such as Lallemand, Inland Island, Escarpment Labs, and The Yeast Bay also list which strains they offer are diastaticus.

See also:

Saccharomyces cerevisiae var boulardii

Although originally designed as a separate species (S. boulardii), it is actually a variety of S. cerevisiae and shares more than 99% of the genetic makeup of S cerevisiae [26].

S. thermantitonum

This species may not be genetically distinct from S. cerevisiae [27][28].

S. paradoxus

In Fermentation

(To do)

Fermentation Under Low pH Conditions

Saccharomyces species and individual strains have a wide range of tolerance to low pH and lactic/acetic acid concentrations, which have been identified as stressors for yeast fermentation. For ideal fermentation conditions for S. cerevisiae, lactic acid should not exceed 0.8%, acetic acid should not exceed 0.5%, and wort should not fall below 4.0 pH. Since pH is on a log-based scale, even small differences in pH (especially below 3.5) can make a large impact on whether or not a given yeast strain is able to ferment. This obviously presents a challenge to brewers when Sour Worting or naturally carbonating with yeast for sour beers [29].

Yeast that fails to bottle condition sour beer may not be due to death of the cells. Rogers et al. [29] published a study that found that yeast used to bottle condition a sour beer at Upland Brewing Co. was still ~80% viable after two weeks, but the surviving cells were small and unbudded, indicating that they ceased growing and entered the stationary phase. This effect has been referred to as "terminal acid shock" [29].

As stated previously, lactic acid and low pH are identified as stressors for yeast, and can affect their ability to carbonate sour beer. Some strains tested display an ability to grow in higher lactic acid concentrations, while others do not, but this does not indicate that they are able to bottle condition sour beer. For example, WLP001 and WY1056 do not grow well in YPD dosed with lactic acid, whereas Lallemand CBC-1 ("Cask & Bottle Conditioned Beer Yeast") can still grow at a pH of 3. WY2007 and WLP300 grow well in moderate levels of lactic acid, but not once the pH gets down to 3. WLP715 Champagne Yeast grows fine in a pH of 3 (although lag time is effected). However, despite being able to grow in YPD with lactic acid dosages, CBC-1 and WLP715 both failed to carbonate an 8% ABV sour beer that had a comparable pH to the pH of the YPD plus lactic acid mediums. It is suggested that this might be due to the combination of stress from high alcohol, acetic acid, low nutrients, low oxygen, and tannins from fruit. Re-hydrating dried yeast may also lead to difficulties carbonating acidic and high ABV (8%+) sour beer due to the stress of desiccation and re-hydration on the yeast [29].

Rogers et al. found an easy solution to carbonating low pH, high ABV beers by first acclimating the yeast to the sour beer. Growing the yeast in YPD plus lactic acid plus ethanol was not enough to acclimate the yeast and reliably carbonate a highly acidic, alcoholic (8% ABV) beer. However, by growing the yeast first in a blend of YPD that was diluted with the sour beer itself in a 1:1 ratio, they found that both CBC-1 and WLP715 were then able to carbonate the sour beer (WLP001, WY1056, WY2007, and WLP300 were not given this treatment). This was explained as exploiting the microbes' resilience and ability to adapt to many environmental conditions by "pre-adapting" the yeast to the harsh conditions of the sour beer [29]. It has been speculated that brewers without access to YPD might be able to achieve similar results by growing the conditioning yeast in sour beer diluted with DME wort and yeast nutrients (Fermaid K and DAP, for example) [30].

A second study showed that a strain of S. cerevisiae was able to adapt and grow in a lab setting to increasing concentrations of lactic acid. After multiple generations and by slowly increasing the amount of lactic acid per generation, the researchers got the pH of the growth media (either raffinose or glucose plus lactic acid) all the way down to pH 2.8. At this low pH, the yeast began to use lactic acid as a food source. This might explain some anecdotal experiences by brewers who have seen the pH of kettle sour beers rise (more evidence is needed to confirm this hypothesis). The researchers found that the gene called ACE2 is likely to be associated with the ability to adapt to low pH conditions. It is also a gene that controls the expression level of other genes, and is also responsible for forming "snowflake-like" structures (multicellular clumps of genetically identical cells that stick together after budding [31]). The yeast strain began to form these "snowflake-like" clumps after being adapted to the low pH environment. Further work should be done to determine which strains of S. cerevisiae might be more easily adapted to low pH environments, or if possibly all strains of S. cerevisiae could be adapted to low pH environments over time [32][33][34].

See also:

Esters

Phenolic Off Flavor Strains

Some strains of S. cerevisiae can convert the ferulic acid, which is found in malted barley and also in higher amounts in wheat, into the phenol 4-vinyl guaiacol (4VG). 4VG is less toxic to microorganisms than the ferulic acid and other hydroxycinnamic acids. It gives a clove-like flavor to beer. While most beer styles consider this an off-flavor, it is an important flavor component for certain styles of beer such as German Hefeweizen, saison, and some Belgian styles. Strains that convert ferulic acid into 4VG during fermentation are known as "phenolic off flavor positive" or "POF+" and are characteristic of wild Saccharomyces, bread yeast, and a small number of brewers yeast. Most strains of brewers yeast, however, were selected for not having this capability, and are known as "phenolic off flavor negative" or "POF-". POF+ strains require two enzymes: phenylacrylic acid decarboxylase (PAD1) and a ferulic acid decarboxylase (FDC1). The PAD1 enzyme creates a precursor required for the FDC1 enzyme to work, which then converts the ferulic acid into 4VG [35].

Yeast produced phenolic/clove aromas tend to dominate over hop aromas in dry hopped beer [36].

See also:

Commercial Farmhouse/Belgian Strains of Saccharomyces

In cooperation with Eric Bandauski [37].

BAC Yeast

Name Source Attenuation Flocculation Temp°F Notes
BY122 Achouffe 72-76% High 64-84 One of many great beer yeast to produce classic Belgian ales. Phenolics develop with increased fermentation temperatures, mild fruitiness and complex spicy character. Similar to WLP550 or WY3522.
BY124 Brasserie Thiriez 77-83% Low 65-77 French Saison yeast starter is a strain that enhances the use of spices and is extremely attenuative yet leaves an unexpected silky and rich mouthfeel in a very dry finished beer.

Produces Saison or farmhouse-style beers that are highly aromatic with clean citrus esters. Expect peppery and spicy notes with no earthiness and low phenols. This strain enhances the use of spices and is extremely attenuative but leaves an unexpected silky and rich mouthfeel in a very dry finished beer. Similar to WY3711. Determined to be Saccharomyces cerevisiae var. diastaticus [23].

BY125 Saison du Pont 76-80% Low 70-85 Belgian Saison Classic farmhouse ale yeast. Very tart and dry on palate with mild fruit. Finishes crisp and mildly acidic. Benefits from elevated temperatures.

Classic farmhouse ale yeast. Spicy and complex aromatics including bubble gum. Very tart and dry on palate with mild fruit. Finishes crisp and mildly acidic. Benefits from elevated fermentation temperatures. Usually slow to attenuate. Similar to WLP565 or WY3724.

BY126 Westmalle 75-80% Medium 64-78 Trappist Big ABV strain is a robust top cropping beer yeast with phenolic character. Trappist Big ABV beer yeast has an alcohol tolerance to 12%. It's ideal for Bière de Garde, as it ferments dry with rich ester profile and a malty palate. Similar to WLP530 or WY3787.
BY128 Esen, Belgium (De Dolle) 72-76% Medium 62-75 This versatile witbier yeast strain can be used in a variety of Belgian style ales. This strain produces a complex flavor profile dominated by spicy phenolics with low to moderate ester production. It is a great strain choice when you want a delicate clove profile not to be overshadowed by esters. It will ferment fairly dry with a slightly tart finish that compliments the use of oats, malted and unmalted wheat. This strain is a true top cropping yeast requiring full fermenter headspace of 33%

A tart, slightly phenolic yeast capable of producing distinctive witbiers and grand cru-style ales alike. Alcohol tolerant. Similar to WY3942.

Bootleg Biology

Name Source Attenuation Flocculation Temp°F Notes
BB22204 - S. arlingtonesis Wild yeast starter jar in Arlington, VA High NA 60-70 This culture ferments extremely cleanly in the low 60’sF (Kölsch and Lager hybrids), and subtle fruity/citrus esters in the higher end of the Ale fermentation range (wheat-centric beers). May produce sulfur aromas during primary fermentation, but those will be eliminated within a couple weeks (allow longer aging if fermenting at lower temperatures). S. arlingtonesis is a higher attenuator than most ale strains, so adjustments made need to be made to grain bills or mash temperatures if a drier beer is not preferred.
BBX0104 – Saison Parfait: New World Saison Blend A unique blend of previously unavailable commercially used Saison cultures. 90-100 Med-High Normal to High Ale Temperatures Saison Parfait is our New World Saison Blend, a new take on the modern saison yeast flavor and aroma profile. Saison Parfait pairs classic pepper & spice saison phenolics with prominent juicy fruit esters that evoke citrus and lemon peel, and a touch of banana for complexity. Even more unique, it finishes with a balanced, full-bodied and silky mouthfeel despite its high attenuation. Saison Parfait means the “Perfect Season”, and is our ode to the fall harvest season. A time for hard work and also celebration. The peasants of rural Flanders and Wallonia created the Saison, and what we now call Farmhouse beers, to drink for sustenance and merriment. Bruegel likely depicted the drinking of Saison beer in his classic paintings of rural country life, “The Harvesters” and “Peasant Wedding”.

Craft Cultures

Name Source Attenuation Flocculation Temp°F Notes
CCYL113 - Belgian Saison Ale Yeast This yeast strain contributes clove flavor and aroma to the finished product. Fruity aromas are also experienced. Commercial pitches only.
CCYL114 - Belgian Ale Yeast To produce any great distinctive Belgian style beer, do ferment with the Belgian Ale Yeast. Flavors emanating from beer produced by this yeast are rich in both spice and phenols and are mildly fruity. Commercial pitches only.
CCYL115 - Trappist Ale Yeast The Trappist Ale Yeast has a unique fruit and plum flavor and aromas. It performs well in high gravity brews. Commercial pitches only.
CCYL116 - Belgian Wit Ale Yeast The original yeast used to produce Belgian Witbier and a variety of other Belgian style ales. Commercial pitches only.
CCYL120 - French Saison Ale Yeast The French Saison Ale Yeast is a versatile strain that works great for Saison or Farmhouse and other Belgian style beers where aromatic (estery), peppery, spicy and citrusy flavors are desired. Might be Saccharomyces cerevisiae var. diastaticus if this strain is the same as WY3711 [23]. Commercial pitches only.
CCYL121 Abbey Ale Yeast Used to produce Trappist, Belgian, Belgian doubles and triples This yeast contributes a fruity characteristics. Excellent alcohol tolerance for high gravity beers. Commercial pitches only.
CCY126 French Ale Yeast Clean strain that complements malt flavor. Low to moderate esters, when fermentation temperature is below 70°F. Moderate plus ester character over 70°F. Low diacetyl production. Good yeast strain for Biere de Garde, blond, amber, brown ales, and specialty beers. Commercial pitches only.
CCYL128 - Belgian Saison Ale Yeast Blend The Belgian Saison Ale Yeast Blend has some phenolic and clove-like flavor and aroma characteristic and fruitier esters than CCYL113. Ferments faster than CCYL113. Commercial pitches only.
CCYL129 - Eagle River Ale Yeast™ Michigan indigenous. The Eagle River Ale Yeast is the second in a series of indigenous Michigan strains. It was isolated from the shore of Lake Superior near Eagle River Michigan. This yeast will produce excellent Belgian style ales. This yeast is rich in both spice and phenols exhibits predominantly fruity esters, similar to a Belgian ale strain. Commercial pitches only.
CCYL130 - Keweenaw Ale Yeast™ Michigan indigenous. The Keweenaw Ale Yeast is the third in a series of indigenous Michigan yeast strains. This yeast was isolated in Michigan's Keweenaw Peninsula. It has prominent spicy phenolics and some fruity esters, very reminiscent of a Saison yeast. Commercial pitches only.
CCYL131 Belgian Wit Ale 2.0 Less Belgian-like phenolics than CCYL116 and more spicy. Will leave a bit more sweetness, and flocculation is higher than CCYL116. Use to produce Belgian Wit, spiced Ales, wheat Ales, and specialty Beers. Commercial pitches only.
CCYL134 Rock Cut Ale Yeast™ Michigan indigenous yeast coming soon. Commercial pitches only.
CCYL138 Rock Cut Ale Yeast II™ Michigan indigenous yeast coming soon. Commercial pitches only.

East Coast Yeast

Name Source Attenuation Flocculation Temp°F Notes
ECY08 Saison Brasserie Several Strains 80+ 75-85 Several saison yeast strains for both fruity and spicy characteristics accompanied with dryness
ECY14 Saison Single Single Strain 76-78 75-82 Smooth, full farmhouse character with mild esters reminiscent of apple pie spice

Escarpment Laboratories

Name Source Attenuation Flocculation Temp°C Notes
Ardennes Belgian Ale 72-80 Med-High 18.3-24.4 A very versatile and production-friendly Belgian ale yeast, producing balanced Belgian esters and spicy notes. One of the rare Belgian strains which flocculates relatively well, making repitching and/or cropping easier when compared to other Belgian yeasts. Alcohol tolerance: high [38].
Classic Witbier 72-78 Med-Low 19-24 Medium alcohol tolerance. A genre-defining Witbier strain, famous for balanced phenol and ester character with slight tartness that emphasizes wheat flavour [38]
Dry Belgian Ale 85+ Med-Low 22-26 Obtained from an American producer of Belgian-style beers. This strain exhibits classic dry Belgian flavours, and displays an aggressive primary fermentation. We especially like this strain for Strong Golden, Tripel, and other Belgian-style beers. NOTE: This strain contains the STA1 gene, meaning it is Saccharomyces cerevisiae var. diastaticus. Many industrial yeasts are diastatic, due to the desire for very high attenuation levels. However extra care must be taken to ensure these yeasts do not cross-contaminate non-diastatic yeasts. Contact us with any questions or concerns. Alcohol tolerance: >12% [38].
Fruity Witbier 70-75 Med-Low 17-24 A Witbier strain which produces lots of complex fruity esters while still prominently displaying classic Witbier character. Medium-low flocculation helps ensure classic Witbier haze. Alcohol tolerance: 12% [38].
Hornindal Kveik Blend Terje Raftevold's Hornindal Kveik 70-80 Med-High 25-35 A selection of two strains from Terje Raftevold's Hornindal Kveik. The blend shows mixed fruity character ranging from tropical fruit to red apple, with supporting notes of caramel. We recommend warm fermentation temperatures (>25ºC), highly fermentable wort and yeast nutrients to ensure complete attenuation. The traditional Norwegian beers are quite malty by comparison to typical ales. Alcohol tolerance: high [38].
Old World Saison Blend 85+ Med 18-25 A characterful blend of two classic Saison strains. Produces complex fruit and black pepper notes along with a reliable, fast and high degree of attenuation. We strongly encourage a free rise fermentation, starting at 22C and rising to ~27C for optimal results. NOTE: One of the strains in this blend contains the STA1 gene, meaning it is Saccharomyces cerevisiae var. diastaticus. Many Saison yeasts are diastatic, due to the desire for very high attenuation levels. However extra care must be taken to ensure these yeasts do not cross-contaminate non-diastatic yeasts. Contact Escparment Labs with any questions or concerns. Alcohol tolerance: High [38].
St-Remy Abbey Ale 72-80 Med 18-24 This yeast strain isolated from a Belgian abbey is an excellent choice for Belgian-style beers, including abbey ales. This strain produces mixed fruity esters, while also highlighting malt aroma. This strain can be used at higher fermentation temperatures without becoming overly phenolic/spicy. Alcohol tolerance: >10% [38].
St. Lucifer Belgian Ale 75-85 Med 20-24.4 A high-character Belgian ale strain, able to produce high gravity beers with strong fruity and medium phenolic character. Excellent for strong golden ales and Tripels, but versatile for all Belgian ale applications. NOTE: This strain contains the STA1 gene, meaning it is Saccharomyces cerevisiae var. diastaticus. Many industrial yeasts are diastatic, due to the desire for very high attenuation levels. However extra care must be taken to ensure these yeasts do not cross-contaminate non-diastatic yeasts. Contact us with any questions or concerns. Alcohol tolerance: >12% [38].
Wild Thing Ontario 75-82 Med 25+ This wild Ontario ale yeast was isolated from an apple in a local orchard. Wild Thing produces distinct clove, spice, and subtle banana and apple fruit aroma. The taste is dry, spicy and clean. This yeast is most comparable to medium-attenuation Belgian-style ale yeasts. May require temperature ramping to 25C to ensure high attenuation. Alcohol tolerance: 9% [38].

GigaYeast

Name Source Attenuation Flocculation Temp°F Notes
GY003 Achouffe Belgian Ale 81-84 (medium gravity) 57-60 (7.7%+ abv) Medium/Low 68-77 Abbey style yeast from the Belgian Ardennes. Produces aromatic, spicy clove-like notes and less fruity aromas than GY014. Moderately flocculant yeast that creates a slightly clearer beer than most Belgians.
GY007 Belgian Mix 79-81 (medium gravity) 67-70 (8.6%+ abv) Low 68-77 A blend of Trappist Ale Yeast combine to create robust attenuation and a complex flavor profile. Spicy and fruity, this blend is slightly more flocculent than many Belgians. Good choice for High Gravity beers.
GY014 Scourmont Abbey Ale 79-81 Low 64-80 Classic Belgian yeast from one of the best known Trappist breweries. A fragrant yeast that produces delicious fruity aroma. Good choice for high gravity beers. Generally, the warmer this yeast is fermented the higher the level of fruit aromas produced.
GY015 Trappist Tripel 70-76 Low 66-74 Trappist Ale yeast from the mother of all Tripels. A balance of fruit and spice with a good malty finish provides a perfect complement for Belgian Ales, Dubbels and Tripels. Attenuation is on the slow side leaving more residual sweetness than our other Belgians. Less esters and phenolics than GY003 and GY014.
GY018 Saison 1 French Brewery 81-83 (medium gravity) 49-53 (6.2%+ abv) Low 64-80 Traditional Saison yeast from a French craft brewery. Strong attenuator that produces a dry beer with a beautiful fragrance and the traditional Saison taste of fruit and pepper. Might be Saccharomyces cerevisiae var. diastaticus if this strain is the same as WY3711 [23].
GY027 Saison Yeast 2 Traditional Saison 79-83 (medium gravity) 44-47 (5.5%+ abv) Low 64-80 Creates the fruity/spicy aroma traditional to the style.  Warmer fermentation temps result in more intense flavor.  Produces a tartness not found in most of our yeast and a slightly sweeter beer than GY018
GY028 Belgian Wit 74-79 Very Low 64-80 Traditional Belgian Wit yeast from one of the classic producers of the style. Creates a delicious spicy nose and a somewhat tart beer. Attenuates dry and leaves a slightly cloudy beer - very low flocculation.
GY047 Saison Blend 80-83 (medium gravity) 49-53 (6.2%+ abv) Low 64-80 A blend of Saison yeast. This Blend is a super robust attenuator that produces a complex flavor profile of fruit and spice.
GY048 Golden Pear Belgian Ale Duvel Moortgat Brewery 78-85 Low 65-80 Traditional yeast from the originator of the Belgian Golden Strong Ale style. Robust attenuation makes this yeast an excellent choice for low or high gravity Belgian and farmhouse style ales. Leaves a dry, slightly tart finish with an estery profile reminiscent of apple and pear with a subdued level of spicy phenolics. This yeast produces a moderate amount of sulfide that will dissipate quickly with conditioning.
GY077 Quebec Abbey Ale Canadian Brewery 75-83 Medium 68-80 From one of the first breweries in North America to create a successful line of traditional Abbey style ales. This Belgian ale yeast creates a malt forward beer with subtle fruity esters and a very small amount of clove notes. Robust attenuation makes this yeast an excellent choice for low or high gravity beers where a slightly sweet malty finish is desired. Perfect for the Belgian Dubbel and Tripel styles.

Imperial Organic Yeast

Name Source Attenuation Flocculation Temp°F Notes
A20 Citrus Unicorn Dust [39] 74-78 Low 67-80 When you want to use Brett, but you don’t. Citrus cranks out orange and lemon aromas along with some tropical fruit. Use this strain at high temps for big ester production. As funky as saccharomyces gets. Same as WLP644 Sacch Trois [39].
B48 Triple Double Westmalle [39] 74-78 Medium 65-77 The perfect strain for your classic abbey ales. Triple Double produces moderate esters with low to no phenolic characteristics. This strain is tried and true and works perfectly in a production environment. Keep an eye on Triple Double, it likes to sit on top of the wort throughout fermentation which may result in a slow fermentation. Similar to Wyeast 3787 and WLP530 [39].
B64 Napoleon Brasserie Thiriez [39] 77-83 Low 65-78 This yeast is an insane wort attenuator. Napoleon will destroy the sugars in your saison and farmhouse beers – even the ones in which most brewer’s strains have no interest. When all is said and done, Napoleon produces very dry, crisp beers with nice citrus aromas. Yeast settling times can be long, usually requiring filtration for bright beers. Similar to Wyeast 3711 [39]. Determined to be Saccharomyces cerevisiae var. diastaticus [23].
B45 Gnome Achouffe [39] 72-76 Medium-High 65-75 The Gnome is the yeast for brewing Belgian inspired beers in a hurry. This strain is extremely flocculent and drops out of the beer quickly after fermentation. Gnome produces a nice phenolic character that goes well with hops, as well as with caramel and toffee flavors. Great for Belgian ales that need to be crystal clear without filtration. Similar to Wyeast 3522 [39].
B51 Workhorse Kasteel [39] 72-77 Medium 65-75 Saison…no problem. Belgian stout, double… yep. Workhorse is the strain to use for a wide variety of brews. Super clean, this fast-attenuating strain has good flocculation characteristics. High alcohol tolerance makes this a great option for big Belgian beers. Similar to Wyeast 1581 [39].
B56 Rustic Brasserie de Blaugies [39] 72-76 Medium 68-80 This unique yeast can be used in your saison, farmhouse ale, or other Belgian styles where high ester levels are important. Rustic typically produces a lot of bubblegum and juicy aromas that compliment complex maltiness. Similar to Wyeast 3726 [39].
B63 Monastic Chimay [39] 74-78 Medium-Low 68-78 This strain is a beautiful yeast for fermenting abbey ales, especially quads; high alcohol and dark Belgian beers. Monastic will produce beers with a high level of phenolic character and esters. It can be slow to begin fermentation but will easily dry out high gravity worts. This strain is a low flocking strain, so expect it to stay suspended for a long time. Similar to Wyeast 1214 and WLP500 [39].
B53 Fish Finder Orval [39] 74-78 Medium 65-73 The classic choice for a Belgian IPA. Fish Finder has a very mild phenolic character balanced with moderate fruitiness. Often used for primary and then finished with a secondary Brettanomyces yeast. Similar to WLP510 [39].
B44 Whiteout Celis White/Hoegaarden [39] 72-76 Medium-Low 62-72 This is the strain for Belgian Wit style beers. Whiteout produces an excellent balance of spicy phenolic character and esters. Along with the necessary aromatics, this strain produces a significant amount of acidity which is perfect for wits and other light colored Belgian ales. Whiteout can be flocculent during fermentation, then become non-flocculent at the end. This may lead to slower than normal fermentation. Similar to Wyeast 3944 and WLP400 [39].

Inland Island Yeast Laboratories

Name Source Attenuation Flocculation Temp°F Notes
INIS-201 Belgian Monk Ale I Monastery brewery in Southern Belgium 72-76 Medium 68-78 High alcohol tolerance and plum like notes create great dark Belgian beers.
INIS-202 Belgian Monk Ale II 73-77 Medium 65-75 High alcohol tolerance. Beer ferments clean with a full body and full malt flavor. Notes of dried fruit.
INIS-203 Belgian Monk Ale III Monastery brewery 74-78 Medium 64-78 High alcohol tolerance. Isolated from a world class monastery brewery known for brewing high gravity ales with complex esters and phenols.
INIS-204 Belgian Monk Ale IV 73-77 Medium 65-75 High alcohol tolerance. Used to brew a beer with a dry and acidic finish but otherwise clean.
INIS-222 Belgian Gnome Ale 72-76 High 65-76 High alcohol tolerance. Distinctive, estery and phenolic profile.
INIS-225 Belgian American Famous Belgian style brewery near Montreal 75-79 Medium 65-80 This yeast produces a beer that is dry with a low ester profile. Phenolics increase as this yeast is fermented at higher temperatures.
INIS-231 Belgian Gold 74-78 Low 64-80 Very high alcohol tolerance. Yeast used to brew a classic strong ale in the Belgian tradition. High alcohol tolerance with mild phenols and fruity esters.
INIS-241 Belgian Wit I 72-76 Medium 64-74 High alcohol tolerance. Used to brew wit style beer. Notes of pear, apple, stone fruit, and a slight acidity/tartness in the finish. Very top heavy.
INIS-242 Belgian Wit Devil 72-76 Medium 62-75 High alcohol tolerance. Similar to Belgian Wit I but with more phenols and clove. Very top heavy requiring a lot of extra space in the fermenter to prevent pushing all of the yeast out of the blow off tube.
INIS-251 French Ale 68-75 Med-High 63-73 This strain produces a clean beer that complements malt with lower ester production than traditional Belgian strains. Excellent yeast choice for a Biere de Garde and specialty beer. Might be Saccharomyces cerevisiae var. diastaticus [23].
INIS-291 Farmhouse: Saison 74-79 Medium 70-95 High alcohol tolerance. A dynamic yeast that produces a wide range of phenols and esters. Notes of strawberry, hay, and spice. Leaves the finish slightly tart and with an excellent mouth feel.
INIS-292 Saison: Belgian I 76-80 Low 70-95 High alcohol tolerance. Traditional saison strain isolated from a premier Belgian Brewery. Fruity, spicy, slightly tart, and leaves the beer dry. Known for stalling towards the end of the fermentation around 5-7 plato, but with additional heat and time will finish.
INIS-293 Saison: Belgian II 78-85 Medium 68-78 Medium alcohol tolerance. Strain is more fruity than Belgian I but from a similar source. Rumored to be a part of a mixed fermentation. This isolated strain is more reliable than Saison: Belgian I but with less depth.
INIS-294 Saison: French 77-83 Low 77-83 High alcohol tolerance. A saison yeast that produces more phenols than the Belgian Saison strains. Notes of pepper and citrus along with other spices. Leaves behind a pleasant mouthfeel in the beer despite being highly attenuative. It is less likely to stall than the Belgian Saisons.
INIS-295 Saison: Phantom 74-79 Low 70-84 This strain produces a saison with subtle spiciness and moderate ester production. The beer finishes dry and tart with no sluggishness like other Belgian Saison yeast.
INIS-296 Saison: Walloon 80-88 Medium 72-80+ This strain produces mild acidity, subtle spicy phenols and some light “funk”. Wide range of phenol and ester production based on fermentation temperature.
INIS-297 Saison: Kveik Norwegian farmhouse 78-83 High 70-100+ A Norwegian Farmhouse strain known for its high fermentation temperature range and above average flocculation. Yeast will produce very few aromatics at the lower temperature range. MTF editor's note: Kveik yeast should not be considered "saison" yeast. See Kveik for more information.
INIS-298 Saison: Baron France 70-80 Medium 70-80 A true Bier-de-Garde yeast from France. Yeast produces a briny flavor and notes of white pepper and straw.
INIS-317 English Ale VII 65-69 Medium 80+ This strain produces a malty beer that is slightly fruity for lower gravity beers. Very high alcohol tolerance makes this a good yeast choice for beers above 10% ABV. INIS-317 English Ale VII has been identified using polymerase chain reaction (PCR) to contain the glucoamylase gene (STA1), which can be an indicator of Saccharomyces cerevisiae var. diastaticus. As such, INIS-317 has the ability to utilize some dextrins which are unfermentable to most species of S. cerevisiae, and thus achieve a very high level of attenuation. However, INIS-317 is not considered a contaminant and will not over attenuate finished beer when a high level of attenuation is expected [40].
INIS-491 Saison: French 77-83 Low 65-77 A saison strain that produces more phenols than the Belgian Saison strains. Notes of pepper and citrus along with other spices. This yeast leaves behind a pleasant mouthfeel in the beer despite being highly attenuative. It is less likely to stall than the Belgian Saison strains. This strain has been identified using polymerase chain reaction (PCR) to contain the glucoamylase gene (STA1), which can be an indicator of Saccharomyces cerevisiae var. diastaticus. As such, INIS-491 has the ability to utilize some dextrins which are unfermentable to most species of S. cerevisiae, and thus achieve a very high level of attenuation. However, INIS-491 is not considered a contaminant and will not over attenuate finished beer when a high level of attenuation is expected [41].

Jasper Yeast LLC

Name Source Attenuation Flocculation Temp°F Notes
JY029 - Belgian Wit I Hoegaarden 70-77 Low 63-76 Spicy and phenolic, with a nice estery finish. Great for witbier, Grand Cru-style wit and specialty beers. Belgian Styles, mainly Belgian Wit and Grand-Cru, but does well in Blonde, Belgian Tripel and Specialty
JY031 - Nova Ale Yeast Ashburn, Virginia 71-80 Very low 68-85 A true local strain! Isolated in Ashburn, Virginia in 2008. The first native Virginia yeast used in commercial beer since prohibition (Farmwell Wheat and Native Son, both Lost Rhino Brewing Company). Higher fermentation temperatures are preferred with this strain. Producer of high levels of fruitiness above 26 ºC (80 ºF), earthy notes are present at lower fermentation temperatures (20 ºC, 68 ºF). Since it is a wild Saccharomyces cerevisiae strain one can expect drift when repitched for many generations.
JY056 - Poperinge Saison Famous Brasserie in Southern Belgian/Northern France region. 79-85 Very low 65-77 Aggressive, attenuative and outspokenly estery and peppery. Great for Saison and Farmhouse style beers at higher temperatures, in the lower range good for more traditional Belgian styles. Good to finish off a beer that has problems fermenting with another yeast.
JY104 - Benedict Abbey Small brewery in Flemish Brabant, Belgium. 75-80 Low 68-77 JY104 was handed to Jasper Akerboom when he toured some small microbreweries in the Netherlands and Belgium by a friendly microbrewer. This strain originally belonged to a small brewery in Flemish Brabant in Belgium. The brewery was acquired by a large macrobrewery, and management decided to do away with this precious yeast. Fortunately passionate homebrewers and beer enthusiasts were able to keep some of the yeast going and you can use it now as well! This strain ferments fast, and aggressive. It can be under pitched easily, and attenuates deep. Great esters and phenols, can be slightly peppery. Flocculates slow, but can withstand spunding without a problem. This yeast is great for lighter colored Belgians, but is great for darker Belgians as well. This strain has not been fully characterized, so we do not know what gravity this yeast will ferment. We do know that it attenuates very well, and the initial tests have indicated that can ferment easily to 10% ABV.
JY110 - NOVA Ale Yeast 2 Northern Virginia 75-80 Low 75-100 This yeast differs from JY031 Nova Ale Yeast 1 by being slight more toned down in the aromatics and flavor department. Isolated in Northern Virginia, this strain is truly local. Power to VA! Since this is a new variety of Saccharomyces cerevisiae, this strain has not been fully characterized yet. Feel free to share your information with us if you use this strain! This strain will be perceived slightly Belgianesque, but at lower fermentation temperatures will be lower in aromatics. Can slow down when temperature is low. Likes it warm.
JY146 - Protocetid Ale Calvert Marine Museum in Solomons, MD. >80 Very low max 90 This yeast is the famous strain isolated from the Calvert Marine Museum in Solomons, MD. This strain was isolated from Protocetid bone, discovered by Jason Osborne, the president and co-founder of Paleo Quest, a non-profit citizen-science organization for the advancement of the sciences of paleontology and geology through material contributions to museum collections, field exploration, scientific publication and education. This yeast is used for the famous Lost Rhino Brewing Company Bonedusters Ale. This yeast is hard to work with, it has the tendency to stop fermenting for a week after 30% attenuation, after which it picks back up and finishes out. Not for the faint of heart! Expect a Belgian character, with some tartness. Keep the desired ABV low during your recipe development, this strain is not suited for high-gravity worts. Finishes crisp and fruity, with a pleasant fizz.

Mainiacal Yeast

Note that available kveik cultures that also have lactic acid bacteria are listed on Mixed Cultures.

Name Source Attenuation Flocculation Temp°F Notes
BB 3 Spontaneous capture 70-82 68-78 This is an interesting strain as it has hints of stone fruit as well as a Saison like quality to it lending citrus notes. Commercial pitches only [42].
Framgarden Norway 70-85 75-110 This Kveik culture is a blend of S. cerevisiae strains and has a light tropical fruit note, hint of apples, light farmhouse straw notes, and a light acidity. Fermenting hotter will allow this yeast to be more expressive. This culture contains no bacteria. See Larsblog and Kveik for more info. Homebrew and commercial pitches available [42].
Granvin Norway 70-85 70-110 A Kveik culture is a blend of S. cerevisiae strains and produces tropical fruitiness that pairs very well with numerous hops. Like the rest of the Kveik cultures, it's more expressive if fermented hotter. No bacteria is present in this culture. Homebrew and commercial pitches available [42]. See also Kveik.
Voss Norway 70-80 70-105 This Kveik culture is a blend of S. cerevisiae strains and has an orange and spicey note to it. Homebrew and commercial pitches available [42]. See also Kveik.
Midtbust Norway 70-86 75-105 A Kveik culture that is a blend of S. cerevisiae strains that lend a lot of stone and tropical fruit notes as well as a light smokiness and acidity. As with many of the Kveiks fermenting hotter leads to more expression. Homebrew and commercial pitches available. More info can be found at Larsblog and Kveik [42].
Lærdal Norway 70-90 80-105 A Kveik culture that is a blend of S. cerevisiae strains from Norway. This culture is clean with hints of stone fruit, light acidity and a farmhouse like barnyard flavor. Like most Kveik fermenting near their max temp leads to much more expression. No bacteria present. Homebrew and commercial pitches available. See Larsblog and Kveik for more info [42].
Wollsæter Norway 70-80 70-100 A 30 yr old Kveik that is a blend of S. cerevisiae strains and an unidentified yeast strain that was revived. Very unique in fermentation as well as the flavor profile. Big stone fruit notes with a light acidity. Like most Kveik fermenting on the hotter spectrum will lead to more flavor expression. Homebrew and commercial pitches available. See Kveik for more info [42].
MYJuicy Maine Maple Tree 70-85 65-80 Wild Sacc strain caught and isolated from a maple tree in Maine. Produces lots of tropical fruit esters. Commercial pitches only [42].
Infectious Behavior 80-100 65-80 Currently this species is a hot topic amongst infections in breweries. As it has the ability to metabolize starches and complex sugars, which most primary yeast fermentation leaves behind. We isolated this out of an infected beer and found it to have very Saison like qualites. Commercial pitches only [42].
Sacc Full of Fruit Wild Capture 70-80 65-78 Stone fruit galore! This Sacc strain creates massive stone fruit notes such as peach, plum and cherry. It works very well for West Coast IPAs, NEIPAs, and a bunch of other styles! We especially like this when in a beer double dry hopped with Belma and Mosaic. Commercial pitches only [42].
Citrus King Wild Capture 70-82 62-80 This particular Sacc c strain produces huge notes of citrus peels and a hint of tropical fruit. It pairs extremely well with the citrus forward new age hops as well as many of the older varieties. We find its perfect for citrusy NE IPAs. This strain also tends to keep the beer hazier given enough protein is also in the wort. Commercial pitches only [42].

Mangrove Jack's Dry Yeasts

Name Source Attenuation Flocculation Temp°F Notes
M21 Belgian Wit High Low 64-77 A traditional top-fermenting yeast that has a good balance between fruity esters and warming spice phenolics. The yeast will leave some sweetness and will drop bright if left long enough. Suitable for Witbier, Grand Cru, Spiced Ales and other specialty beers.
M29 French Saison Ale (previously M27) [43] Very High Med 79-90 Characterful beers with spicy, fruity and peppery notes ideal for Belgian Saison or farmhouse style beer. Suited for brewing all Belgian ales, including Quadruples of up to 14% abv. M29 description: French Saison yeast is an exceptional, highly attenuative top-fermenting ale yeast, creating distinctive beers with spicy, fruity and peppery notes. Ideal for fermentation of farmhouse style beer [44]. Confirmed to be Saccharomyces cerevisiae var. diastaticus [45].
M31 Belgian Tripel Very High Med 64-82 Provides a fantastic complex marriage of spice, fruity esters, phenolics and alcohol. It is also very attenuative with a high alcohol tolerance making it perfect for a range of Belgian styles. Suitable for Belgian Tripel and Trappist style beers.
M41 Belgian Ale Very High Med 64-82 Spicy and phenolic, this yeast emulates the intensity and complexity of some of the best monastic breweries in Belgium. High attenuation and alcohol tolerance allow you to brew a huge range of Belgian beers. Suitable for Belgian Strong Golden and Belgian Strong Dark Ales.
M47 Belgian Abbey Yeast High High 64-77 Moderately alcohol tolerant with fewer phenols than Belgian Ale, this yeast is exceptionally fruity with hugely complex esters and is highly flocculant.

Omega Yeast Labs

Name Source Attenuation Flocculation Temp°F Notes
Abbey Ale C - (OYL-018) 74-78 Medium-Low 68-78 From a famous Trappist brewery, this yeast produces the distinctive fruitiness and plum characteristics. Excellent yeast for high gravity beers, Belgian ales, Dubbels and Tripels. Compares to WLP500 and WY1214. Commercial pitches only.
Belgian Ale A (OYL-024) 72-85 High 65-78 Versatile strain for the production of classic Belgian style ales. This strain produces a beautiful balance of delicate fruit esters and subtle spicy notes, with neither one dominating. Unlike many other Belgian style strains, this strain is highly flocculent and results in bright beers. Compares to Compares to WLP550 and WY3522. Available to homebrewers.
Belgian Ale D (OYL-019) 74-78 Low 64-80 The best choice for brewing golden strong ales. This alcohol tolerant strain will produce a complex ester profile balanced nicely with subtle phenolics. Malt flavors and aromas will remain even with a well attenuated dry, tart finish. It may continue to produce CO2 for an extended period after packaging or collection. Compares to WLP570 and WY1388. Commercial pitches only.
Belgian Ale DK (OYL-049) 73-80 Medium 67-70 Clean Belgian type ale yeast. Good for Belgian style pale ales and amber ales. Biscuity, ale-like aroma with accentuated hop flavor and bitterness. Slight sulfur will be produced during fermentation, which can give the yeast a lager-like flavor profile. Compares to WLP515. Commercial pitches only.
Belgian Ale O (OYL-046) 74-80 Medium 66-72 A Trappist style ale yeast. Produces dry beer with slight acidic finish, but cleaner than OYL-018 and OYL-028. Good choice for high gravity beers, Belgian ales, Dubbels and Tripels. Compares to WLP510. Commercial pitches only.
Belgian Ale R (OYL-020) 73-82 Medium 65-75 Great choice for use in Belgian dark strong ales. This strain has a relatively “clean profile” which allows a rich malt and distinctive ethanol character to shine. Delicate dried fruit esters can be produced when used at higher fermentation temperatures or in a high gravity wort. Compares to WLP540 and WY1762. Commercial pitches only.
Belgian Ale W (OYL-028) 74-78 Medium 64-78 Classic strain for brewing Belgian Dubbel or Belgian Tripel. This strain produces a nice balance of complex fruity esters and phenolics, making it desirable for use in other Belgian style ales as well. A flocculent, true top cropping yeast (additional headspace is recommended), that will work over a broad temperature range. Makes a great Belgian style “house” strain. Compares to WLP530 and WY3787. Available to homebrewers.
Belgian Dark Ale A (OYL-040) 74-79 Medium 65-80 Belgian ale yeast that is a high acid producer with balanced ester and phenol production. High alcohol tolerance. Spicy, tart, and dry on the palate with a very complex finish. Compare to WY3822. Commercial pitches only.
Belgian Saison I (OYL-027) 76-80 Low 70-95 Most widely used farmhouse ale yeast. A traditional yeast that is spicy with complex aromatics, including bubble gum. It is very tart and dry on the palate with a mild fruitiness. Will yield a crisp, mildly acidic finish that will benefit from elevated fermentation temperatures. This strain is notorious for a rapid and vigorous start to fermentation, only to stick around 1.035 S.G. Fermentation will finish, given time and warm temperatures. Warm fermentation temperatures, at least 90°F (32°C), or the use of a secondary strain can accelerate attenuation. Compares to WLP565 and WY3724. Commercial pitches only.
Belgian Saison II (OYL-042) 74-79 Medium 70-84 This strain produces complex esters balanced with earthy/spicy notes. Slightly tart and dry with a peppery finish. A perfect strain for Farmhouse ales and Saisons. Compares to WY3726. Commercial pitches only.
Belgian Wheat (OYL-029) 72-76 Medium 64-74 Produces beers with moderate esters and minimal phenolics. Apple, bubblegum, and plum-like aromas blend nicely with malt and hops. This strain will finish dry with a hint of tartness. Compares to WY3942. Commercial pitches only.
Biere de Garde (OYL-039) 74-79 Low 70-84 Ferments well with low to moderate ester production and subtle spiciness. Malty and full on the palate with initial sweetness. Finishes dry and slightly tart. Compares to WY3725. Commercial pitches only.
French Saison (OYL-026) 77-83 Low 65-77 Versatile strain that produces Saison or farmhouse style beers as well as other Belgian style beers that are highly aromatic (estery), peppery, spicy and citrusy. This strain enhances the use of spices and aroma hops, and is extremely attenuative but leaves an unexpected silky and rich mouthfeel. This strain can also be used to re-start stuck fermentations or in high gravity beers. Compares to WY3711. Determined to be Saccharomyces cerevisiae var. diastaticus [23]. Commercial pitches only.
Grand Cru (OYL-023) 72-76 Low 63-76 Widely used strain in the production of Witbier, Grand Cru, sweet mead and cider. Produces spicy phenolics which are balanced nicely by a complex ester profile. The subtle fruit character and dry tart finish will complement wheat malt, orange peel and spice additions typical of Wits. Compares to WLP720 and WY3463. Commercial pitches only.
Saisonstein's Monster (OYL-500) 80-90 Low 65-78 The first in our line of hybrid strains. This strain is a genetic hybrid resulting from the mating of strains OYL-026 and OYL-027, created by and available exclusively from Omega Yeast. Less phenolic and more fruit character than 026. Exhibits some of the bubble gum character of 027. Omega Yeast Labs Exclusive. This might be a hybrid of S. boulardii and S. cerevisiae var. diastaticus [46]. Available to homebrewers.
Wit (OYL-030) 72-76 Medium 62-75 Produces a complex flavor profile dominated by spicy phenolics with low to moderate ester production. It is a great strain choice when you want a delicate clove profile not to be overshadowed by esters. It will ferment fairly dry with a slightly tart finish that compliments the use of oats, malted and unmalted wheat. This strain is a true top cropping yeast requiring full fermenter headspace of 33%. Compares to WLP400 and WY3944 vs Omega Yeast Labs Exclusive. Commercial pitches only.
HotHead Ale (OYL-057) Single strain isolate from traditional Norwegian Kveik brewing yeast. Stein Langlo, Stranda, Norway via Lars Marius Garshol. See NCYC 4021 [47][48] 75-85 Medium-High 62-98 A remarkable ale strain of Norwegian origin that has an astoundingly wide temperature range (62F-98F) with little difference in flavor profile across the whole range. It has a unique fruitiness that makes it complementary to modern hop varieties. See Kveik for more information. Available to homebrewers. MTF notes: recommended fermenting at the higher temperature range. Visual fermentations characteristics are unique: long lasting krausen even after fermentation has finished [49].
Voss Kveik (OYL-062) Another kveik strain from Voss, Norway. See this Lars Garshol blog article as well for this yeast's history. 75-82 Medium 68-98° F (20-37° C) A traditional Norwegian “kveik” strain from the farmhouse brewery of Sigmund Gjernes in Voss, Norway, this strain (like OYL-057 HotHead) is capable of fermenting across a broad temperature range with little change in flavor profile. Voss Kveik is non-phenolic and produces a beer with moderate citrus notes. It would pair very well with citrusy and fruity hops. This strain is not fast at the low end of the range so don’t be afraid to pitch in the middle to upper part of the temperature range. The Voss kveik was originally a blend of at least 3-4 strains, however only one strain was cultured by Omega [50] See Kveik for more information.

RBY Laboratories

Name Source Attenuation Flocculation Temp°F Notes
RBY41 French Saison Brasserie Thiriez 77-83 Low 65-75 Determined to be Saccharomyces cerevisiae var. diastaticus [23].
RBY58 - Fantome Saison Clone #1 Fantome 70-80 Low 75-85

RVA Yeast Labs

Name Source Attenuation Flocculation Temp°F Notes
RVA 261 Saison I Dupont 65-75 Med 75+ fruity, bubblegum esters with all the spice and pepper that makes Saison so appealing
RVA 262 Saison II Brasserie Thiriez 75-82 Med 67-77 French origin, this strain produces a bit less of the fruity, bubblegum esters with less spice and pepper then RVA 241. Determined to be Saccharomyces cerevisiae var. diastaticus [23].
RVA 263 Ghost Ale Fantome 74-84 Med 65-80 Ripened fruit esters and a crisp earthy finish can be achieved even at lower temperatures with this Belgian farmhouse strain
RVA 806 Lickinghole Creek Ale Virginia’s LHCB farm 78-85 Med 68-74 Citrus esters, a nose of sweet honey and a dash of phenolic spice, this strain will complement a variety of dry Belgian style beers. We highly recommend this strain for Belgian triple and Saison.  

Saccharolicious

Name Source Attenuation Flocculation Temp°F Notes
Demonical Popular yeast strain from a well-known Belgian brewery. Because of its ester-dominated fermentation profile, this yeast strain is often used in strong Belgian ales. Other beer styles where this yeast strain can be used are Belgian-style IPA, Belgian blond and Tripel.
Trappist O Relatively clean Belgian yeast from a Trappist brewery in the Ardennes. A good choice for most Belgian ales, but especially strong pale Belgian ales. In combination with Brett I, this strains can be used for brewing Belgian specialty ales.
Wheat I Belgian Wit yeast from a brewery in West Flanders.
Castle Alcohol tolerant yeast strain suitable for strong and sweet ales. This yeast strain originates from a West Flemish brewery.
Gnome Yeast strain from a brewery in the Belgian Ardennes. Very versatile strain that fits most Belgian ale styles because of its balanced fermentation profile.
Pixie Slightly phenolic and spicy yeast strain from West Flanders. This is a versatile yeast strain that fits both malty and hoppy beers.

SouthYeast Labs

Name Source Attenuation Flocculation Temp°F Notes
P1 Musserweissen Dwarf Peach (Clemson, SC) 78.7% Low Use for Wit, Heffe, Saison, Kölsch. "Medium" acidity. Banana, peach esters; citrus peel and clove phenolics. 4-6 weeks in primary. Hazy, notes of champagne [51].
N3 Native Cider Nectarine (South Carolina) 83.2% High Use for light Belgian ales, cider, wine. "No acidity". Apple cider esters; light pepper spice phenolics. 3-4 weeks in primary [51].
B3 Farmhouse Ale Blueberry (Clemson, SC) 79.3% Low Use for saison, farmhouse ales. "Medium acidity". Tart esters; straw spice phenolics. 4-6 weeks in primary. It produces notes of straw and spice - enough to pique the palate but not enough to offend. It even produces enough acid to leave a noticeable tartness in the beer. It will leave the beer hazy with yeast at the end of its 4-6 week fermentation [51].
HS2 New Abbey Ale Honeysuckle (Walland, TN) 78% Medium Use for Belgian and Abbey type ales. "Low acidity". Red wine esters; cracked pepper corn phenolics. 3-4 weeks in primary. Full flavor and complex. [51].
N1 Native Strong Ale Nectarines (Clemson, SC) High N1 was one of the first wild yeasts we ever captured and a good portion of why we fell in love with wild yeast. N1 is our workhorse yeast, finishing semi-dry and clean with a hint of champagne. It flocculates well after 3-4 weeks. Good for pale ales, strong ales, mead and cider.

The Yeast Bay

Name Source Attenuation Flocculation Temp°F Notes
Saison Blend 80 Med 70-78 Blend of 2 yeast strains, Flavors of pepper, grapefruit, Orange zest
Wallonian Farmhouse 81-88 Med 68-78  Slight earthy funk and tart character to the beer; we recommend controlling the dryness by adjusting the mash temperature or adding malts or adjuncts to the mash tun that will lend some body and residual sweetness to the beer. Although it can be fermented at lower temps, for full flavor it is recommended to start fermentation in the 70°F's, and let it free-rise to the low to mid 80°F's [52]. Determined to be Saccharomyces cerevisiae var. diastaticus [53].
Wallonian Farmhouse II 80-82 Med-Low 68-80  This is a single strain of Saccharomyces cerevisiae isolated from the same source as our Wallonian Farmhouse strain, a well-known brewery hailing from the Walloon region of Belgium. Slightly less attenuative and exhibiting a more restrained phenolic and expressive ester profile than our original Wallonian Farmhouse, this yeast is a great choice for any classic saison style beer in which a balance of fruitiness and rustic farmhouse character is desired. Wallonian Farmhouse II works very well in conjunction with Brettanomyces owing to its robust and complex ester and phenol profile, so well that it has the honor of being the dominant saison strain in our new Saison/Brettanomyces Blend II culture [54].
Wallonian Farmhouse III 80-82 Med-Low 68-80  This is a single strain of Saccharomyces cerevisiae isolated from a well-known brewery hailing from the Walloon region of Belgium. This strain is as attenuative as our original Wallonian Farmhouse and exhibits a more balanced profile of ester and phenols. This yeast is similar to a classic saison strain offered by many other yeast manufacturers, without the slow/low attenuation and stalling issues often observed in those cultures. Wallonian Farmhouse III works very well in conjunction with Brettanomyces owing to its balanced and complex ester and phenol profile [55].
Saison Blend II 80-86 Med 68-80 This saison blend is the Saccharomyces portion of our Farmhouse Sour Ale, available to you as a result of popular demand from the commercial brewing crowd. This combination of Saccharomyces strains embodies the balanced fusion of the two foremost saison flavor/aroma characters, fruitiness and earthiness. Each Saccharomyces strain in this blend produces flavor compounds that serve as the yin to the other's yang, and the result is an exceptionally complex yet balanced flavor and aroma profile. One strain will serve to create an ester profile of grapefruit and orange zest, while the other will produce a mild earthiness and spiciness. Close your eyes while drinking a beer fermented with this blend, and you'll feel like you're laying on freshly turned earth in an old citrus grove. Contains a strain that is determined to be Saccharomyces cerevisiae var. diastaticus [56].
Dry Belgian Ale 85-100 Med-High 68-74 Dry Belgian Ale is single strain of Saccharomyces cerevisiae isolated from a unique golden strong ale. The profile is a complex and balanced mix of apple, pear and light citrus fruit with some mild spicy and peppery notes. The apparent attenuation of this strain ranges anywhere from 85-100%, depending upon the mash profile and the grist composition. For a yeast that's as dry as it is, it creates beers with a surprising amount of balance even without the use of specialty grains or adjuncts. While we haven't completed our own tests in house, this yeast is used at the brewery from which it was isolated to make big beers that are in the neighborhood of 12-16% ABV and sufficiently dry. Use Dry Belgian Ale as a primary fermenter in any big Belgian beer, or to unstick that pesky stuck fermentation. Determined to be Saccharomyces cerevisiae var. diastaticus [57].
Northeastern Abbey 77-81 Med-Low 68-73 This yeast was isolated from a beer crafted by a well-known producer of Belgian-style ales in the Northeastern United States. This yeast produces a very mild spiciness and earthy flavor and aroma which is complemented by a subtle but magnificent array of fruity esters, including pear and light citrus fruit. The brewery from which this strain was isolated uses it in a very versatile manner across an array of Belgian styles. We prefer using this yeast for any and all light Belgian beers, including Wit, Belgian Pale and Belgian Blond, in addition to any experimental fruit beers in which a more unique and robust flavor and aroma profile is desired. Expect this yeast to produce a large, thick krausen.
Sigmund's Voss Kveik Norwegian farmhouse 80-85 Med-High 70-100 Sigmund's Voss Kveik yeast is a single strain of Saccharomyces cerevisiae isolated from a sample of kveik generously provided by Sigmund Gjerens via Lars Garshol. Traditionally used in the production of Norwegian Farmhouse Ale, this strain is a fast fermenter with good attenuation, a light earthy spiciness, marked tartness and unique ester profile of orange peel. This strain is prone to forming incredibly large flocs unlike any other yeast we've seen before, yet still remains highly attenuative. Sigmund's Voss Kveik also exhibits the ability to ferment wort over a large temperature range, 70 - 100 ºF, without major changes to the flavor profile or production of any harsh phenolics or fusel alcohols. This yeast will exhibit a slightly more restrained ester profile and ferment a little slower at cooler fermentation temperatures, and quickly produce a drier beer with a slightly more pronounced ester profile at warmer fermentation temperatures. We highly recommend taking this into the high end of temperature range, 90-100°F. Lars Marius Garshol recommends underpitching with high oxygen to get the most character out of this yeast [58]. See Kveik for more information.
Funktown Pale Ale 78-80 Medium-Low 68-74 Funktown Pale Ale is a blend of our Vermont Ale strain and a unique strain of Brettanomyces that is well suited for primary fermentation Saccharomyces "Bruxellensis" Trois. The combination of the citrus/peach esters from the Vermont Ale strain and the very light funk and pineapple/mango esters from the Brettanomyces produces a unique flavor and aroma profile that is fruit-forward. Expect this blend to finish drier than the Vermont Ale. We recommend following a similar fermentation scheme as is used for the Vermont Ale, fermenting at 67-69 ºF for 3-4 days, and then raising the temperature to 72 ºF until a stable gravity is reached. Approximately 58 billion cells/vial. Contains a strain that is determined to be Saccharomyces cerevisiae var. diastaticus [59].
Flanders Specialty Ale 80-90 Medium 68-80 This is a single strain of Saccharomyces cerevisiae isolated from a fascinating Belgian producer of a wide array of traditional Belgian beer styles. This is a versatile yeast that will ferment fairly dry and produce a balanced flavor and aroma profile laced with a myriad of esters and phenols. While fermenting to dryness similar to our Dry Belgian Ale, there remains a pleasant fullness in the mouthfeel and a malt backbone that shines. If you would like the final gravity to remain a bit higher, we recommend mashing around 156 F [60]. Approximately 58 billion cells/vial.

White Labs

Name Source Attenuation Flocculation Temp°F Notes
WLP072 - French Ale 69-75 Med-High 63-73 Clean strain that complements malt flavor. Low to moderate esters, when fermentation temperature is below 70°F. Moderate plus ester character over 70°F. Low diacetyl production. Good yeast strain for Biere de Garde, blond, amber, brown ales, and specialty beers. Seasonal Availability: May - Jun.
WLP400 - Belgian Wit Ale Hoegaarden/Celis [61] 74-78 Low-Med 67-74 Slightly phenolic and tart, this is the original yeast used to produce Wit in Belgium.
WLP410 - Belgian Wit II Ale Moortgat Brouwerij (via Ommegang?) [61] 70-75 Low-Med 67-74 Less Belgian-like phenolics than WLP400 and more spicy. Will leave a bit more sweetness, and flocculation is higher than WLP400. Use to produce Belgian Wit, spiced Ales, wheat Ales, and specialty Beers.
WLP500 - Monastery Ale Chimay [61] 75-80 Low-Med 65-72 From a Belgian monastery where monks traditionally made beer, this yeast produces the distinctive fruitiness and plum characteristics. Excellent yeast for high gravity beers, Belgian ales, Dubbels and Tripels.
WLP510 - Bastogne Belgian Ale Orval [61] 74-80 Med 66-72 A high gravity, Trappist style ale yeast. Produces dry beer with slight acidic finish. More ‘clean’ fermentation character than WLP500 or WLP530. Not as spicy as WLP530 or WLP550. Excellent yeast for high gravity beers, Belgian ales, Dubbels and Tripels.
WLP515 - Antwerp Ale De Koninck [61] 73-80 Med 67-70 Clean, almost lager like Belgian type ale yeast. Good for Belgian type pales ales and amber ales, or with blends to combine with other Belgian type yeast strains. Biscuity, ale like aroma present. Hop flavors and bitterness are accentuated. Slight sulfur will be produced during fermentation, which can give the yeast a lager like flavor profile. Seasonal Availability: Nov - Dec.
WLP530 - Abbey Ale Westmalle [61] 75-80 Med-High 66-72 Used to produce Trappist style beers. Similar to WLP500, but is less fruity and more alcohol tolerant (up to 15% ABV). Excellent yeast for high gravity beers, Belgian ales, Dubbels and Tripels.
WLP540 - Abbey IV Ale Rochefort [61] 74-82 Med 66-72 An authentic Trappist style yeast. Use for Belgian style ales, Dubbels, Tripels, and specialty beers. Fruit character is medium, in between WLP500 (high) and WLP530 (low). This strain benefits from extra oxygenation. Seasonal Availability: Jul - Aug.
WLP545 - Belgian Strong Ale 78-85 Med 66-72 From the Ardennes region of Belgium, this classic yeast strain produces moderate levels of ester and spicy phenolic character. Typically results in a dry, but balanced finish. This yeast is well suited for Belgian dark strongs, Abbey Ales, and Christmas beers.
WLP550 - Belgian Ale Achouffe [61] 78-85 Med 68-78 Saisons, Belgian Ales, Belgian Reds, Belgian Browns, and White beers are just a few of the classic Belgian beer styles that can be created with this yeast strain. Phenolic and spicy flavors dominate the profile, with less fruitiness then WLP500.
WLP565 - Belgian Saison Brasserie Dupont (Saison Dupont) [61] 65-75 Med 68-75 May stall, use at higher temps to prevent. Considered the "Dupont" strain.
WLP566 - Saison II Vieille Provision Saison Dupont [61] and Brasserie de Blaugies 78-85 Med 68-78 Saison strain with more fruity ester production, Fast Fermenter.
WLP568 - Belgian Ale Yeast Blend 70-80 Med 70-80 Belgian style ale and Saison strains. The strains work in harmony to create complex, fruity aromas and flavors. Yeast strain encourages complete fermentation in a timely manner. Phenolic, spicy, earthy, and clove like flavors are also created.
WLP570 - Belgian Golden Ale Duvel (Moortgart) via McEwans [61] 73-78 Low 68-75 From East Flanders, versatile yeast that can produce light Belgian ales to high gravity Belgian beers (12% ABV). A combination of fruitiness and phenolic characteristics dominate the flavor profile. Some sulfur is produced during fermentation, which will dissipate following the end of fermentation. Does not ferment maltotriose [62]. Determined to be Saccharomyces cerevisiae var. diastaticus [63].
WLP575 - Belgian Style Ale Yeast Blend WLP500, WLP530, WLP550 [61] 74-80 Med 68-75 A blend of Trappist type yeast (2) and one Belgian ale type yeast. This creates a versatile blend that can be used for Trappist type beer, or a myriad of beers that can be described as 'Belgian type'.
WLP585 Belgian Saison III 70-74 Med 68-75 Produces beer with a high fruit ester characteristic, as well as some slight tartness. Finishes slightly malty, which balances out the esters. Low levels of clove phenolics. Great yeast choice for a summer Saison that is light and easy-drinking. Seasonal Availability: Jul - Aug. Reported by Richard Preiss of Escarpment Laboratories that WLP585 has the STA1 gene that codes for Saccharomyces cerevisiae var. diastaticus, but reported that it takes weeks before it hyper-attenuates [64]
WLP590 French Saison Ale 73-80 Med 69-75 Unique yeast strain producing farmhouse-style beers with a phenolic “bite” and moderate ester compounds. Producing a cleaner aroma profile than other farmhouse styles, this yeast is versatile and highly attenuating. Seasonal Availability: May - Jun. Determined to be Saccharomyces cerevisiae var. diastaticus [23][65].
WLP644 Saccharomyces "Bruxellensis" Trois 85%+ Low 70-85 Medium-High alcohol tolerance. This Belgian strain produces a slightly tart beer with delicate characteristics of mango and pineapple. Can also be used to produce effervescence when bottle-conditioning. Formally named Brettanomyces bruxellensis Trois, it was re-classified to be Saccharomyces, and probably S. cerevisiae [66]. White Labs classifies this as a "wild Saccharomyces" [67]. Trois cannot ferment lactose [68]. It does not produce significant amounts of acetic or lactic acid, even under aerobic conditions [69]. Therefore if acid (lactic or acetic) is found in a Trois beer, contamination would be the cause. It also does not produce phenols (POF-), but does produce higher amounts of esters than most strains of S. cerevisiae [70] Approx. 500 million cells per mL; homebrew vials are approx. 17.5 billion cells at 35 mL [71]. PurePitch packages now contain the same pitching rate as other S. cerevisiae White Labs strains (1.5 billion to 3.0 billion cells per mL). One example from their "Yeastman" database for lot # 1035203 (02/19/2017) shows 2.3 billion cells per mL [72]. Determined to be Saccharomyces cerevisiae var. diastaticus [73].
WLP6788 Norwegian Farmhouse Ale A kveik strain from a farm called Muri in Olden, Sogn og Fjordane, Norway (6788 is the zip code). It was used in traditional farmhouse brewing up until 1990, then left in dried form in a building on the farm. The son on the farm revived it with difficulty last year and has been using it in modern home brewing since [74]. 80 Medium 98 (no one knows the optimal temperature currently) [74] Purchase from Bryggselv.no. US customers send an email to post @ bryggselv.no. See source information on Lars Garshol's blog for brewing notes. Species currently unknown, but most closely related to bayanus / pastorianus / uvarum / arboricolus [75]. See Kveik for more information.
WLP700 Flor Sherry Yeast 80-100 (may not be accurate) 70-100 15%+ ABV alcohol tolerance. Report by Johnny Horn for 100% WLP700 in the following characteristics: aroma: slightly savory, slight worcestershire sauce, earthy, cidery. Flavour: sweet nutty caramel, light acidity, honey, apple, brown sugar, strawberry/cherry, dry woody, slightly thin mouthfeel. Has its own odd (but pleasant) character and complexity. Final pH was 3.5, which might indicate a blend with lactic acid bacteria (1g/l aged Fuggles at 60 mins, and 1g/l aged Fuggles at 10 mins). Pitch was 1.0 (M cells / ml / ° P) at 19C and fermentation chamber was set to 21-22C for duration. Final gravity was stable at 1.024 from 1.065 at about 4 weeks, indicating that the advertised attenuation may not be accurate [76]. Can be a slow fermenter on its own. See also the WL FAQ.

Wild Pitch Yeast

Name Source Attenuation Flocculation Temp°F Notes
WPY125 Oak tree in Red River Gorge, KY Sweet and floral aromas are produced by this strain, and it yields a typical Belgian phenolic flavor [77].

Wyeast

Name Source Attenuation Flocculation Temp°F Notes
1214 - Belgian Abbey™ 74-78 Med-Low 68-78 A widely used and alcohol tolerant Abbey yeast that is suitable for a variety of Belgian style ales. This strain produces a nice ester profile as well as slightly spicy alcohol notes. It can be slow to start; however, it attenuates well.
1388 - Belgian Strong Ale™ 74-78 Low 64-80 The classic choice for brewing golden strong ales. This alcohol tolerant strain will produce a complex ester profile balanced nicely with subtle phenolics. Malt flavors and aromas will remain even with a well attenuated dry, tart finish. This strain is prone to stalling at approximately 1.035; racking or slight aeration will encourage it to finish fermentation.
1762 - Belgian Abbey II™ 73-77 Med 65-75 An excellent yeast strain for use in Belgian dark strong ales. This strain has a relatively “clean profile” which allows a rich malt and distinctive ethanol character to shine. Delicate dried fruit esters can be produced when used at higher fermentation temperatures or in a high gravity wort.
3463 - Forbidden Fruit™ 72-76 Low 63-76 A widely used strain in the production of Witbier and Grand Cru. This yeast will produce spicy phenolics which are balanced nicely by a complex ester profile. The subtle fruit character and dry tart finish will complement wheat malt, orange peel and spice additions typical of Wits. Available from April through June 2017.
3522 - Belgian Ardennes™ 72-76 High 65-76 One of the great and versatile strains for the production of classic Belgian style ales. This strain produces a beautiful balance of delicate fruit esters and subtle spicy notes, with neither one dominating. Unlike many other Belgian style strains, this strain is highly flocculent and results in bright beers.
3538 - PC Leuven Pale Ale 75-78 High 65-80 This vigorous top fermenting Belgian style strain produces a distinct spicy character along with mild esters. Phenolics developed during fermentation may dissipate with conditioning. 3538 is an excellent choice for a wide variety of Belgian beer styles. Private Collection for Spring 2015 (available April-June 2015).
3711 - French Saison Brasserie Thiriez 77-83 Low 65-77  Peppery, spicy and citrusy. This strain enhances the use of spices and aroma hops, and is extremely attenuative but leaves an unexpected silky and rich mouthfeel. See this MTF thread for fermentation tips. Determined to be Saccharomyces cerevisiae var. diastaticus [23].
3724 - Belgian Saison™ Dupont 76-80 Low 70-95  It is very tart and dry on the palate with a mild fruitiness. Expect a crisp, mildly acidic finish that will benefit from elevated fermentation temperatures. Notorious for a rapid start, only to stick. Fermentation will finish, at least 90°F. The same or very similar to the "Dupont" strain.

This strain was sequenced by Lance Shaner of Omega Yeast Labs as possibly being the species S. boulardii; it is not known if other labs who offer the "Dupont" strain offer the same isolate because bottles of Dupont saison have reportedly been found to have multiple and varying strains over time [78].

3725 - Biere De Garde Soy-Erezée, Belgium / Fantôme 74-79 Low 70-84 Low to moderate ester production with subtle spiciness. Malty and full on the palate with initial sweetness. Finishes dry and slightly tart. Ferments well with no sluggishness. Available from April through June 2017.
3726 - Farmhouse Ale Blaugies, Belgium 74-79 Med 70-84 This strain produces complex esters balanced with earthy/spicy notes. Slightly tart and dry with a peppery finish. A perfect strain for farmhouse ales and saisons. Available from July through September 2015.
3739 - Flanders Golden Ale™ 74-79 Med-Low 64-80 3739-PC is a well-balanced strain, producing moderate levels of both fruity esters and spicy phenols while finishing dry with a hint of malt. Robust alcohol and temperature tolerance plus strong attenuation make it a good candidate for high-gravity fermentations. Available from April through June 2016.
3787 - Trappist High Gravity™ 74-78 Med 64-78 A classic strain for brewing Belgian Dubbel or Belgian Tripel. This Abbey strain produces a nice balance of complex fruity esters and phenolics, making it desirable for use in other Belgian style ales as well. A flocculent, true top cropping yeast (additional headspace is recommended), that will work over a broad temperature range. This strain makes a great Belgian style “house” strain.
3822 - Belgian Dark Strong Ale™ 74-79 Med 65-80 Oud Bruin/Flanders Brown, Fruit beers, Belgian Golden and Dark Strong Ales, Kriek and Framboise, Belgian Specialty Ale

Profile: 3822-PC is a unique Saccharomyces strain which produces spicy, phenolic and distinctly tart aromas and flavors, which can be increased through warmer fermentation temperatures. Very tart and dry on the palate, complemented well by blending with fruit. Available from April through June 2016.

3864 - Canadian/Belgian Ale™ 74-79 Med 65-80 This alcohol tolerant strain produces complex and well-balanced Belgian Abbey style ales. Banana and fruit esters are complemented nicely with mild levels of phenolics and hints of acidity. Ester levels may be elevated by increasing gravity and fermentation temperatures. May produce some sulfur at cool fermentation temperatures. Available from April through June 2016.
3942 - Belgian Wheat™ 72-76 Med 64-74 Isolated from a small Belgian brewery, this strain produces beers with moderate esters and minimal phenolics. Apple, bubblegum and plum-like aromas blend nicely with malt and hops. This strain will finish dry with a hint of tartness.
3944 - Belgian Witbier™ 72-76 Med 62-75 This versatile Witbier yeast strain can be used in a variety of Belgian style ales. This strain produces a complex flavor profile dominated by spicy phenolics with low to moderate ester production. It is a great strain choice when you want a delicate clove profile not to be overshadowed by esters. It will ferment fairly dry with a slightly tart finish that compliments the use of oats, malted and unmalted wheat. This strain is a true top cropping yeast requiring full fermenter headspace of 33%.

Other Labs

Name Lab Source Attenuation Flocculation Temp°F Notes
Safbrew T-58 Dry Fermentis 70 Med 12-25°C (53.6-77°F) ideally 15-20°C (59-68°F) A specialty ale yeast selected for its estery, somewhat peppery and spicy flavor. Yeast with a good sedimentation: forms no clumps but a powdery haze when re-suspended in the beer.
Safbrew BE-256 Dry Fermentis 82 High 12-25°C (53.6-77°F) ideally 15-20°C (59-68°F) Active dry yeast recommended to brew a diversity of beers amongst which abbey style beers known for their high alcohol content. It ferments very fast and reveals subtle and well-balanced aromas. To maintain the aromatic profile at the end of the fermentation, we do recommend to crop the yeast as soon as possible after fermentation.
SafAle BE-134 Fermentis 90 Low 25-29°C (77-84°F) This typical yeast strain is recommended for Belgian Saison-style beers and is characterized by a particularly high attenuation. It gives fruity aromas with a spicy character such as clove notes. This strain will produce highly refreshing and drinkable beers. Confirmed by the company to be Saccharomyces cerevisiae var. diastaticus [79][80]. This might be the same strain as WY3711.
SafeAle WB-06 Fermentis 86 Low 18-24°C (64-75 °F) This typical yeast strain is recommended for wheat beer fermentations and produces subtle estery and phenol flavor notes (POF+) such as clove notes typical of wheat beers. Confirmed by the company to be Saccharomyces cerevisiae var. diastaticus [81]
Lallemand Belle Saison - DRY Lallemand High 59-95 [82] Belle Saison is also a prodigious sulfur producer, so extended conditioning may be necessary. Verified to be Saccharomyces cerevisiae var. Diastaticus, and killer neutral [82][83][84]. Belle Saison yeast is killer neutral, which means that killer wine strains will not kill it [82]. See this MTF thread for more information on this strain. This might be the same strain as WY3711 [85]. Formerly branded as "Danstar".
Lallemand Abbaye Belgian Ale Yeast - DRY Lallemand Med-High Low 63-80 Abbaye is an ale yeast of Belgian origin selected for its ability to produce great Belgian style beers including high gravity beers such as Dubbel, Trippel and Quads. The propagation and drying processes have been specifically designed to deliver high quality beer yeast that can be used simply and reliably to help produce ales of the finest quality. Formerly branded as "Danstar".

Starters

(To do)

Storage

For long term storage (3 months to potentially 2+ years), slants are a good option. For instructions on how to make slants at home capable of storing any microbe for potentially 2+ years, see Bryan's video on Sui Generis Brewing (requires a pressure cooker).

See Also

Additional Articles on MTF Wiki

MTF Threads

External Resources

References

  1. ref needed
  2. 2.0 2.1 2.2 "Killer (Zymocidal) Yeasts." Brewing and Distilling Yeasts. Graham G. Stewart. 2018.
  3. Yeast viral killer toxins: lethality and self-protection. Manfred J. Schmitt & Frank Breinig. 2006.
  4. 4.0 4.1 Rima Hatoum, Steve Labrie, and Ismail Fliss. 2012.
  5. Advances in Microbial Physiology, Volume 22. Academic Press, Sep 15, 1981. Pg 94-95.
  6. Conversation with Bryan of Sui Generis Blog on MTF on Killer Factor for Saccharomyces. 11/16/2015.
  7. Strains of Yeast Lethal to Brewery Yeasts. A.P. Maule and P.D. Thomas. 1972.
  8. 8.0 8.1 A New Wine Saccharomyces cerevisiae Killer Toxin (Klus), Encoded by a Double-Stranded RNA Virus, with Broad Antifungal Activity Is Evolutionarily Related to a Chromosomal Host Gene. Nieves Rodríguez-Cousiño, Matilde Maqueda, Jesús Ambrona, Emiliano Zamora, Rosa Esteban and Manuel Ramírez. 2011
  9. Non-Saccharomyces killer toxins: Possible biocontrol agents against Brettanomyces in wine? S. Afr. J. Enol. Vitic. vol.36 n.1 Stellenbosch. 2015.
  10. 10.0 10.1 10.2 10.3 Antimicrobial Agents Produced by Yeasts. T. Buyuksirit, H. Kuleasan. 2014.
  11. 11.0 11.1 Yeast Interactions in Inoculated Wine Fermentation. Maurizio Ciani, Angela Capece, Francesca Comitini, Laura Canonico, Gabriella Siesto and Patrizia Romano. 2016.
  12. 12.0 12.1 Saccharomyces cerevisiae variety diastaticus friend or foe? Spoilage potential and brewing ability of different Saccharomyces cerevisiae variety diastaticus yeast isolates by genetic, phenotypic and physiological characterization. Meier-Dörnberg T, Kory OI, Jacob F, Michel M, Hutzler M. 2018. doi: 10.1093/femsyr/foy023.
  13. 13.0 13.1 Incidence of Saccharomyces cerevisiae var. diastaticus in the Beverage Industry: Cases of Contamination, 2008–2017. Tim Meier-Dörnberg, Fritz Jacob, Maximilian Michel, and Mathias Hutzler. 2017. MBAA Technical Quarterly; http://dx.doi.org/10.1094/TQ-54-4-1130-01.
  14. STA10: A gene involved in the control of starch utilization by Saccharomyces. Julio Polaina, Melanie Y. Wiggs. 1983.]
  15. Structural analysis of glucoamylase encoded by the STA1 gene of Saccharomyces cerevisiae (var. diastaticus). Ana Cristina Adam, Lorena Latorre-Garcia, Julio Polaina. 2004.
  16. Richard Preiss. Milk the Funk thread about STA1 gene correlation to glucoamylase production. 12/31/2017.
  17. 17.0 17.1 17.2 Matthew Peetz of Inland Island and Tobias Fischborn of Lallemand. "Master Brewers Association Podcast" 12/25/2017.
  18. Wade Begrow. "Recent notable microbiological contaminations of craft beer in the United States". Presentation poster at EBC 2017. Retrieved 11/19/2017.
  19. Caroline Whalen Taggart. Milk The Facebook post on how quickly diastaticus ferments. 02/09/2018.
  20. Factors That Control the Utilization Of Wort Carbohydrates by Yeast. G. G. Stewart, I. Russell, and A. M. Sills. MBAA Technical Quarterly, Vol. 20, No. 1, 1983.
  21. District Court, Boulder County, Colorado. Case Number 2017CV31132. Filed 11/14/2017.
  22. Adi Hastings. Milk The Funk Facebook Group post on non-diastaticus strains with high attenuation. 02/27/2018.
  23. 23.00 23.01 23.02 23.03 23.04 23.05 23.06 23.07 23.08 23.09 23.10 Richard Preiss. Milk The Funk thread on diastaticus. 11/18/2017.
  24. MTF thread on STA1 gene and White Labs strains that might have it or not. Milk The Funk Facebook group. 12/07/2017.
  25. Richard Preiss. Milk The Funk Facebook group post on WLP570 and WLP585 being diastaticus. 02/08/2018.
  26. Saccharomyces boulardii. Wikipedia. Retrieved 12/07/2017.
  27. Search on : CBS strain database. CBS. Retreived 04/12/2016.
  28. Conversation with Richard Preiss on MTF regarding S. thermantitonum. 04/12/2016.
  29. 29.0 29.1 29.2 29.3 29.4 Terminal acidic shock inhibits sour beer bottle conditioning by Saccharomyces cerevisiae. Cody M. Rogers, Devon Veatch, Adam Covey, Caleb Staton, Matthew L. Bochman. 2016.
  30. Conversation with Richard Preiss and Tamir Danon on acclimating yeast to sour beer for conditioning on MTF. 03/24/2016.
  31. "Life’s Secrets Sought in a Snowflake". Emily Singer. Quantum Magazine. 11/03/2015. Retrieved 12/27/2016.
  32. Evolutionary engineering reveals divergent paths when yeast is adapted to different acidic environments. Eugene Fletcher, Amir Feizi, Markus M.M. Bisschops, Björn M. Hallström, Sakda Khoomrung, Verena Siewers, Jens Nielsen. 2016.
  33. Origins of multicellular evolvability in snowflake yeast. William C. Ratcliff, Johnathon D. Fankhauser, David W. Rogers, Duncan Greig & Michael Travisano. 2015.
  34. Conversation on MTF with Richard Preiss about yeast adaption to low pH environments. 12/27/2016.
  35. The Impact of Simple Phenolic Compounds on Beer Aroma and Flavor. Michael Lentz. 2018. doi: 10.3390/fermentation4010020.
  36. "Recent Advances in Controlling Hoppy Aroma in Beer." Daniel C. Sharp. OSU Brewing Science Presentation.
  37. Eric Bandauski's Yeast Strain Guide
  38. 38.0 38.1 38.2 38.3 38.4 38.5 38.6 38.7 38.8 Escarpment Labs Yeast website. Strain Collection. Retrieved 02/27/2018.
  39. 39.00 39.01 39.02 39.03 39.04 39.05 39.06 39.07 39.08 39.09 39.10 39.11 39.12 39.13 39.14 39.15 39.16 39.17 Private correspondence with IOY by Dan Pixley.09/04/2015.
  40. INIS-317 English Ale VII. Inland Island website. Retrieved 02/27/2018.
  41. INIS-491 Saison: French. Inland Island website. Retrieved 12/07/2017.
  42. 42.00 42.01 42.02 42.03 42.04 42.05 42.06 42.07 42.08 42.09 42.10 Private correspondence with Justin Amaral by Dan Pixley. 01/24/2018.]
  43. Conversation with Paul Finney about M29/M27. 03/21/2016.
  44. Mangrove Jack's Craft Serieis Dried Yeast spec sheet. Retrieved 03/21/2016.
  45. Robbert Roost private email correspondance with Mangrove Jack customer service; forwarded to Dan Pixley. 12/14/2017.]
  46. Lance Shaner. Milk The Funk Facebook group on OYL-500. 09/18/2017.
  47. NYCY website. NCYC 4021. Retrieved 09/14/2015.
  48. Conversation with Lance Shaner on MTF regarding OYL-057 source. 09/14/2015.
  49. Conversation with Adi Hastings on MTF regarding HotHead. 04/02/2016.
  50. Conversation with Lance Shaner and Lars Marius Garshol on MTF. 01/04/2016.
  51. 51.0 51.1 51.2 51.3 SouthYeast Labs Yeast Catalog. Retrieved 3/2/2015.
  52. Conversation with Nick Implellitteri and Ed Coffey on MTF. 08/19/2015.
  53. Wallonian Farmhouse. The Yeast Bay website. Retrieved 03/20/2018.
  54. WALLONIAN FARMHOUSE II. The Yeast Bay website. Retrieved 02/06/2017.
  55. WALLONIAN FARMHOUSE III. The Yeast Bay website. Retrieved 02/06/2017.
  56. Saison Blend II. The Yeast Bay website. Retrieved 03/20/2018.
  57. Dry Belgian Ale. The Yeast Bay website. Retrieved 03/20/2018.
  58. Conversation with Lars Marius Garshol on MTF. 02/10/2016.
  59. Funktown Pale Ale. The Yeast Bay website. Retrieved 03/20/2018.
  60. FLANDERS SPECIALTY ALE. The Yeast Bay website. Retrieved 02/06/2017.
  61. 61.00 61.01 61.02 61.03 61.04 61.05 61.06 61.07 61.08 61.09 61.10 61.11 Mr. Malty website. Yeast Strain Sources. Retrieved 01/20/2016.
  62. Kristoffer Krogerus. "Decoding some White Labs strains from the Gallone et al. 2016 paper". Suregork Loves Beer blog. 10/22/2017. Retrieved 10/23/2017.
  63. WLP570. White Labs website. Retrieved 02/28/2018.
  64. Richard Preiss. Milk The Funk Facebook group post on WLP570 and WLP585 being diastaticus. 02/08/2018.
  65. White Labs website. "WLP590 French Saison Ale Yeast". Retrieved 02/28/2018.
  66. Archive of MTF discussions regarding Trois genetic analysis results.
  67. White Labs 644 Explanation. 04/09/2015. Retrieved 5/2/2015.
  68. Lance Shaner's results of fermenting Trois with lactose on MTF. 10/12/2015.
  69. Conversation with Lance Shaner of Omega Labs on MTF. 01/17/2016.
  70. Richard Preiss. Milk The Funk Facebook post on Trois flavor profile. 02/06/2018.
  71. Homebrewing Reddit post. 02/26/2016.
  72. Paul Illa. Milk The Funk Facebook group. 05/01/2017.
  73. White Labs website. "WLP644 Saccharomyces "Bruxellensis" Trois". Retrieved 02/28/2018.
  74. 74.0 74.1 Conversation with Lars Garshol. 6/4/2015.
  75. Accugenix Report from White Labs on WLP 6788. Posted by Eskild Alexander Bergan on Milk The Funk. 6/4/2015.
  76. Johnny Horn. Milk The Funk post on WLP700 characteristics. 09/07/2017.
  77. Wild Pitch Yeast catalog. Retrieved 1/2/2018.
  78. Lance Shaner. Milk The Funk Facebook group post on S. boulardii. 09/18/2017.
  79. Fermentis BE-134 Spec Sheet. Retrieved 02/10/2018.
  80. Private email correspondence with a Fermentis representative by Jeremy Johns; email forwarded to Dan Pixley for verification. 11/21/2017.
  81. Fermentis BE-134 Spec Sheet. Retrieved 02/10/2018.
  82. 82.0 82.1 82.2 Marie, Coppet from Lallemand. Private correspondence with Martin Etchart; forwarded to Dan Pixley
  83. Conversation on MTF with Pierre Hugo Houle regarding Danstar Belle Saison yeast. 01/25/2017.
  84. Lallemand Brewing website. "BELLE SAISON BELGIAN SAISON-STYLE YEAST". Retrieved 11/20/2017.
  85. MTF Thread on Belle Saison. 11/20/2017.