Saccharomyces

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. 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:

• A systematic forest survey showing an association of Saccharomyces paradoxus with oak leaf litter.
• The interaction of Saccharomyces paradoxus with its natural competitors on oak bark.
• The natural ecology of Saccharomyces yeasts.
• Associated MTF thread.

History of Domestication

• "A family tree for brewer's yeast" a review of a study on the family tree of brewer's yeast by Lars Garshol.
• Kristoffer Krogerus's attempt to decode the strains in the above mentioned study ("Domestication and Divergence of Saccharomyces cerevisiae Beer Yeasts") and a redraw of the dendrogram family tree of ale yeasts as well as a spreadsheet that makes a best guess to map the strains in the study to actual White Labs strains.
  • See also comments by Krisoffer on this MTF thread.
• Another study that sequenced 28 strains of S. cerevisiae to find a family tree: Distinct Domestication Trajectories in Top-Fermenting Beer Yeasts and Wine Yeasts.
• YouTube presentation by Kevin Verstrepen:

Killer Wine Yeast

Many wine yeast strains are known to be "killer" yeast strains. In Saccharomyces, killer strains are genetically determined to produce 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 the cell wall component called "β-1,3-glucan", 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 . Neutral strains do not produce toxins, nor are they killed by them . Almost all ale and lager strains are sensitive to the toxins produced by killer strains . 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 yeast from other genra, such as Hanseniaspora spp., Kluyveromyces lactis, Candida albicans, Candida dubliniensis, Candida kefir and Candida tropicalis, and the K1, K2 and K28 killer strains of S. cerevisiae . However, none of the toxins secreted by killer strains of Saccharomyces have been found to kill Brettanomyces . 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 . The activity of the toxin is greatest during the log phase of growth, and decays during the stationary phase of fermentation .

Various other yeast species have the ability to produce toxins that effect a range of other yeasts and bacteria . For example, strains of the yeast species Candida pyralidae , Wickerhamomyces anomalus, Kluyveromyces wickeramii, Torulaspora delbrueckii and Pichia membranifaciens have been found to produce toxin that inhibits Brettanomyces . In addition, the toxin produced by Wickerhamomyces anomalus and Williopsis markii have been found to inhibit a wide range of spoilage and pathogenic fungi . 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 . Strains of Torulaspora delbrueckii have been shown to kill killer strains of S. cerevisae (wine strains), as well as to kill Pichia species .

• For the implications of this on re-yeasting beer with wine yeast at packaging, see the Packaging page.
• For concerns about using bottle dregs from commercial sour beers that are bottled with wine or champagne yeast, see Commercial Sour Beer Dregs.
• Lallemand chart of wine yeasts and their Killer Factor.
• Another chart of wine yeast strain and killer factor (column labeled "Competitive Factor").
• Chris Lewis's write up on wine yeast character/Killer Factor on Lewy Brewing Blog.
• Shea Comfort notes on wine yeast on the BBB.

Saccharomyces cerevisiae var. diastaticus

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. This variant can produce extracellular glucoamylase that can break down starches into simpler sugars that are then fermented by the yeast and cause over-carbonation. 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 . 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 mins). This report is directly contradicted by White Labs regarding their strains with this gene WLP590, WLP099, and WLP045 (it is likely that the strains reported by other microbiologists to be diastaticus are the same as these White Labs strains, but this has not been verified). This yeast has also reportedly been detected using LCSM agar plates, although other species of wild Saccharomyces yeast can grow on this media (~18 mins) and PCR DNA analysis is required to give a positive identification of diastaticus. Documented attenuation percentages above 75% for any strain of S. cerevisiae is also an indicator that the strain is diastaticus . Var. diastaticus contamination in breweries has been a recent hot topic, and the source of some contaminations have been suspected to come from certain yeast suppliers (namely White Labs) .

S. cerevisiae var diastaticus can grow at 37°C and can also remain viable at refrigeration temperatures . WY3711 saison yeast, which originated from Basserie Thiriez, has been determined to be this subspecies . 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).

Some hints as to which 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 .

See also:

• Sui Generis Brewing blog articles on using practical methods of PCR to identify diastaticus and other contamination for small breweries.
• This MTF thread on White labs lawsuit, identification via PCR, and general contamination problems.
• ASBC "Rapid Methods for Detecting Saccharomyces diastaticus, a Beer Spoilage Yeast, Using the Polymerase Chain Reaction."
• Reddit thread on detecting diastaticus.
• MBAA Podcast on diastaticus Part 1.

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 .

S. thermantitonum

This species may not be genetically distinct from S. cerevisiae .

• MTF thread on S. Thermantitonum.

S. paradoxus

• "Saccharomyces species experiment #1: Paradoxus Ale," by Matt Humbard on A PhD in Beer Blog.

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 .

Yeast that fails to bottle condition sour beer may not be due to death of the cells. Rogers et al. 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" .

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 .

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 . 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) .

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 ). 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 .

See also:

• Lactic Acid
• Acid Shock Starters
• The Sour Hour interview with Dr. Matt Bochman
• "Biochemist finds solution to 'acid shock' in craft brewers' sour beer production", article on Phys.org.
• "Quick Sour, then what? Acid Tolerance of Brewer’s Yeast" by Michael Tonsmeire

Esters

• "Esters and Fusel Alcohols" by Scott Janish.
• "Understanding Esterification", Sour Beer Blog.

Phenolic Off Flavor Strains

(To do)

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

• Kristoffer Krogerus's blog article on removing POF gene from Saccharomyces hybrids.

Commercial Farmhouse/Belgian Strains of Saccharomyces

In cooperation with Eric Bandauski .

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 .
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 . 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
Old World Saison Blend		85+	Med	18-25	A high-character blend of two classic Saison strains. Produces complex fruit and black pepper notes along with reliable and high attenuation. Alcohol tolerance: High.
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%.
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 insure classic Witbier haze. Alcohol tolerance: 12%.

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 .
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	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 .
B48 Triple Double	Westmalle	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 .
B64 Napoleon	Brasserie Thiriez	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 . Determined to be Saccharomyces cerevisiae var. diastaticus .
B45 Gnome	Achouffe	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 .
B51 Workhorse	Kasteel	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 .
B56 Rustic	Brasserie de Blaugies	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 .
B63 Monastic	Chimay	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 .
B53 Fish Finder	Orval	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 .
B44 Whiteout	Celis White/Hoegaarden	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 .

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 .
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-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 .

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.

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.
M27 Belgian Ale / M29 French Saison Ale (new name)		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 . Might be Saccharomyces cerevisiae var. diastaticus .
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 . 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 . 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	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 .
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 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 .
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 .
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 .
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 .
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 .
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. .
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.
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 .
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 .
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.
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.
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 . 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.
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 . Approximately 58 billion cells/vial.

White Labs

• 1.5 to 3.0 billion per milliliter; homebrew PurePitch® packages contain 60-120 billion cells. See White Labs FAQ for an explanation on varying cell counts in PurePitch® packages, and the public Yeastman database.
• See White Labs list of Belgian yeast strains and characteristics, including phenols/spiciness.
• See The WL Vault, which contains many non-conventional yeasts and bacteria.

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	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?)	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	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	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	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	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	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	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)	65-75	Med	68-75	May stall, use at higher temps to prevent. Considered the "Dupont" strain.
WLP566 - Saison II	Vieille Provision Saison Dupont	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	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 .
WLP575 - Belgian Style Ale Yeast Blend	WLP500, WLP530, WLP550	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.
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 .
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 . White Labs classifies this as a "wild Saccharomyces" . Trois cannot ferment lactose . It, also, does not produce significant amounts of acetic or lactic acid, even under aerobic conditions . Therefore if acid (lactic or acetic) is found in a Trois beer, contamination would be the cause. Approx. 500 million cells per mL; homebrew vials are approx. 17.5 billion cells at 35 mL . 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 .
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 .	80	Medium	98 (no one knows the optimal temperature currently)	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 . 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 . 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 .

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 .
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 .
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 . This might be the same strain as WY3711.
Danstar Belle Saison - DRY	Lallemond		High		59-95	Belle Saison is also a prodigious sulfur producer, so extended conditioning may be necessary. Verified to be Saccharomyces cerevisiae var. Diastaticus, and killer neutral . Belle Saison yeast is killer neutral, which means that killer wine strains will not kill it . See this MTF thread for more information on this strain. This might be the same strain as WY3711 .
Danstar Abbaye Belgian Ale Yeast - DRY	Lallemond		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.

Starters

(To do)

• For information on mixed culture starters, see Mixed Culture Starters.

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).

• MTF thread on freezing yeast for storage, with link to HBT article.
• "Maintaining A Healthy Yeast Bank Long Term", article on HBT.
• Bryan of Sui Generis blog guide to freezing & refrigerating yeast for homebrewers:

See Also

Additional Articles on MTF Wiki

• Sour Worting
• Lactobacillus
• Pediococcus
• Brettanomyces
• Debaryomyces
• Spontaneous Fermentation
• Kveik

MTF Threads

• Study that shows heat shock increases glycerol production.

External Resources

• Maltose Falcons Guide To Saisons - Saison yeast profiles
• Coming Clean: A New Method of Washing Yeast with Chlorine Dioxide.
• Esters - Table of esters and their smells.
• The Saccharomyces family, by Lars Garshol.
• VLB Berlin pure yeast cultures.
• Yeast Strain Comparison Chart (White Labs, Wyeast) - information by Kristen England on Mr. Malty website.
• In depth article by Tracy Aquilla on yeast respiration, "How Yeast Use Oxygen".
• A blog article about brewing with Saccharomyces paradoxus by Matt Humbard on A Ph.D. in Beer blog.
• "Here It Is, the Genetic Family Tree of Beer", article on the Verstrepen/White Labs paper on the family tree of yeast.
• YouTube taste comparison of three Yeast Bay Saison cultures, and tips from Drew Beechum on fermenting with saison yeast.
• Wine Strain Chart from Winemakers.com.
• Scott Labs wine yeast inventory, with descriptors of each yeast for thiols, mouthfeel, etc.