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'''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 [[Saccharomyces#Killer_Wine_Yeast|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]], [[Kveik#Commercial_Availability|Kveik]], and [[Nonconventional Yeasts and Bacteria]] charts for other commercially available cultures.
==Genus==
The origin of ''S. cerevisiae'' and other species of ''Saccharomyces'', as well as the entire genus itself, is likely to be Asia, according to genomic studies. The presence of ancestral polymorphism (variations on the same genetic sequence between populations) suggests that these species arose during a short period of time during which a lot of genetic inheritance was shared before the speciation events occurred. Despite this, genetic differentiation between species of ''Saccharomyces'' is higher than in plants and animals <ref name=Peris_2023">[https://www.nature.com/articles/s41467-023-36139-2 Peris, D., Ubbelohde, E.J., Kuang, M.C. et al. Macroevolutionary diversity of traits and genomes in the model yeast genus Saccharomyces. Nat Commun 14, 690 (2023). https://doi.org/10.1038/s41467-023-36139-2.]</ref>.
Some species could have originated in other parts of the world. For example, ''S. uvarum'' and ''S. eubayanus'' in South America, ''S. jurei'' and ''S. paradoxus'' in Europe, and ''S. arboricola'' in Oceana <ref name=Peris_2023" />. These speciation events occurred around 5-10 million years ago during the warm climate of the [https://www.britannica.com/science/Miocene-Epoch Miocene ephoc]<ref>[https://www.sciencedirect.com/science/article/pii/S0092867418313321 Xing-Xing Shen, Dana A. Opulente, Jacek Kominek, Xiaofan Zhou, Jacob L. Steenwyk, Kelly V. Buh, Max A.B. Haase, Jennifer H. Wisecaver, Mingshuang Wang, Drew T. Doering, James T. Boudouris, Rachel M. Schneider, Quinn K. Langdon, Moriya Ohkuma, Rikiya Endoh, Masako Takashima, Riichiroh Manabe, Neža Čadež, Diego Libkind, Carlos A. Rosa, Jeremy DeVirgilio, Amanda Beth Hulfachor, Marizeth Groenewald, Cletus P. Kurtzman, Chris Todd Hittinger, Antonis Rokas, Tempo and Mode of Genome Evolution in the Budding Yeast Subphylum, Cell, Volume 175, Issue 6, 2018, Pages 1533-1545.e20, ISSN 0092-8674, https://doi.org/10.1016/j.cell.2018.10.023.]</ref>. Humans played a particularly important role in the genetic divergence of some strains of ''S. cerevisiae'' (see [[Saccharomyces#History_of_Domestication|History of Domestication]] below).
See also:
* [https://en.wikipedia.org/wiki/Saccharomyces ''Saccharomyces'' at Wikipedia''.]
* [https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/saccharomyces ScienceDirect AI generated topic article.]
==Species==
''Saccharomyces cerevisiae'' is the type species of the genus ''Saccharomyces'', although ''Saccharomyces paradoxus''and is well-known and highly studied. it is used in industrial production of baking and fermentation as well as bioenergy and biomedical fields. Wholke-genome sequencing was completed in 1996, and since then the body of scientific knowledge on the species of ''S. cerevisiae's'' closest relative, is likely older and more globally ubiquitous higher than any other eukaryotic system. More recently, whole-genome sequencing has also been performed on other species of ''S. cerevisiaeSaccharomyces''. , which has resulted in models for studies on population genomics, as well as insight into the evolution of this genus <ref>ref needed<[https://academic.oup.com/femsyr/article/20/3/foaa013/ref> Many previously recognized species 5810663 Haya Alsammar, Daniela Delneri, An update on the diversity, ecology and biogeography of the Saccharomyces have been consolidated or reassigned to another genus, commonly ''Zygosaccharomyces''FEMS Yeast Research, Volume 20, Issue 3, May 2020, foaa013, https://doi.org/10.1093/femsyr/foaa013.]</ref>. Species of ''Saccharomyces'' other than ''S. cerevisiae'' (and only certain strains of ''S. cerevisiae'') are generally unable to efficiently ferment maltotriose, although some can ferment maltose (such as ''S. eubayanus'') <ref name="Cubillos_2019">[https://onlinelibrary.wiley.com/doi/10.1002/yea.3380 Bioprospecting for brewers: Exploiting natural diversity for naturally diverse beers. F.A. Cubillos, B. Gibson, N. Grijalva‐Vallejos, K. Krogerus, J. Nikulin. 2019. DOI: https://doi.org/10.1002/yea.3380.]</ref>.
{| class="wikitable sortable"
|-
| ''S. uvarum'' || Found in nature and fermented drinks, especially cold fermentated drinks <ref>[https://academic.oup.com/femsle/article/192/2/191/554355 Saccharomyces uvarum, a proper species within Saccharomyces sensu stricto. Andrea Pulvirenti, Huu-Vang Nguyen, Cinzia Caggia, Paolo Giudici, Sandra Rainieri, Carlo Zambonelli. 2000. DOI: https://doi.org/10.1111/j.1574-6968.2000.tb09381.x]</ref>. || Contains horizontal gene transfers from ''S. cerevisiae'' and ''S. kudriavzevii'' due to human-controlled beverage fermentation <ref>[https://www.ncbi.nlm.nih.gov/pubmed/28779574 Many interspecific chromosomal introgressions are highly prevalent in Holarctic Saccharomyces uvarum strains found in human-related fermentations. Albertin W, Chernova M, Durrens P, Guichoux E, Sherman DJ, Masneuf-Pomarede I, Marullo P. 2018. DOI: 10.1002/yea.3248.]</ref>.
|-
| ''S. jurei'' || Tolerant of cooler fermentation temperatures; discovered on oak tree bark (''Quercus robur'') in France. || Tolerant of high osmotic stress and high sugar concentrations. Discovered by Naseeb et al., 2017; 2018 <ref>[https://pubmed.ncbi.nlm.nih.gov/28639933/ Naseeb, S., James, S.A., Alsammar, H., Michaels, C.J., Gini, B., Nueno-Palop, C., Bond, C.J., McGhie, H., Roberts,I.N., Delneri, D., 2017. Saccharomyces jureisp. nov., isolation and genetic identification of a novel yeast species from Quercus robur. Int. J. Syst. Evol. Microbiol. 67.DOI: https://doi.org/10.1101/2021.01.08.425916.]</ref><ref>[https://pubmed.ncbi.nlm.nih.gov/30097472/ Naseeb, S., Alsammar, H., Burgis, T., Donaldson, I., Knyazev, N., Knight, C., Delneri, D., 2018. Whole genome sequencing, de novo assembly and phenotypic profiling for the new budding yeast species Saccharomyces jurei. G3 Genes, Genomes, Genet. 8, 2967–2977. https://doi.org/10.1534/g3.118.200476.]</ref>.
|-
| ''S. bayanus'' || Found only in brewing environments || A complex hybrid between ''S. eubayanus'', ''S. uvarum'', and ''S. cerevisiae'' <ref>[https://www.pnas.org/doi/abs/10.1073/pnas.1105430108 Microbe domestication and the identification of the wild genetic stock of lager-brewing yeast. Diego Libkind, Chris Todd Hittinger, Elisabete Valério, Carla Gonçalves, Jim Dover, Mark Johnston, Paula Gonçalves, and José Paulo Sampaio. DOI: https://doi.org/10.1073/pnas.1105430108. 2011.]</ref>.
|-
|}
See also:
* [https://www.preprints.org/manuscript/202107.0423/v1 Brewing Efficacy of Non-Conventional Saccharomyces Non-Cerevisiae Yeasts; 2021.]
===''S. cerevisiae''===
====General Info====
* [https://www.youtube.com/channel/UCEyCSmOUfkp_QPH1PClAxVQ/videos Escarpment Labs video presentations on yeast basics] and [https://www.youtube.com/watch?v=d5TFluCM3_4 Why do yeast cells need oxygen? | Yeast Basics 2: Lecture 1].
* [https://www.escarpmentlabs.com/single-post/2020/07/14/fan-its-what-beer-yeast-craves Escarpment Labs blog post on FAN requirements for different strains of brewers yeast.]
* [https://webcache.googleusercontent.com/search?q=cache%3ADKUyEeRhaNYJ%3Ahttps%3A%2F%2Fwww.novozymes.com%2F-%2Fmedia%2FProject%2FNovozymes%2FWebsite%2Fwebsite%2Fdocument-library%2FAdvance-your-business%2FBioenergy%2FYeast-Micronutrient-Requirements-2017.pdf%20&cd=1&hl=en&ct=clnk&gl=us "Yeast Micronutrient and Growth Factor Requirements," by Novozymes North America Technical Service - Bioenergy.]
* [http://macau.uni-kiel.de/receive/dissertation_diss_00018537?lang=en The natural ecology of Saccharomyces yeasts.]
* [https://www.facebook.com/groups/MilkTheFunk/permalink/1910439962317542/ Associated MTF thread.]
Geographically speaking, studies such as [https://www.nature.com/articles/s41467-023-36139-2 Peris et al (2023)] have used DNA sequencing to determine that many species of ''Saccharomyces'' originated in East Asia <ref name=Peris_2023" />.
====History of Domestication====
* [https://www.garshol.priv.no/blog/426.html "The Yeast Family Tree Grows," by Lars Marius Garshol, 10-26-2021.]
* [https://www.cell.com/cell/fulltext/S0092-8674(16)31071-6 Domestication and Divergence of Saccharomyces cerevisiae Beer Yeasts, by Gallone et al (2016); the first look at the domesticated ''S. ceresiae'' family tree and the grouping of two major genetic groups for domesticated ale yeasts: Beer 1 and Beer 2.]
** [http://www.garshol.priv.no/blog/374.html "A family tree for brewer's yeast" a review of a study on the family tree of brewer's yeast by Lars Garshol]. See also [http://www.garshol.priv.no/blog/390.html Lars's write up on the history of people reusing yeast as opposed to spontaneously fermenting].
** [http://www.cell.com/current-biology/fulltext/S0960-9822(16)30984-8 Distinct Domestication Trajectories in Top-Fermenting Beer Yeasts and Wine Yeasts, by Gonçalves et al (2016).]
** [https://www.nature.com/articles/s41467-018-05106-7 The origin and adaptive evolution of domesticated populations of yeast from Far East Asia, by Duan et al (2018); a study showing evidence for initial domestication of yeast in the Far East Asia.]
** [https://www.nature.com/articles/s41586-018-0030-5 Genome evolution across 1,011 Saccharomyces cerevisiae isolates, by Peter et al (2018), which indated indicated that domestication of yeast might have begun in Asia.] See also [https://www.theatlantic.com/science/archive/2018/04/yeast-sequencing-china/557930/ this article] and the [https://www.facebook.com/groups/MilkTheFunk/permalink/2056777254350478/ associated MTF thread].** [https://www.nature.com/articles/s41586-020-2889-1 A yeast living ancestor reveals the origin of genomic introgressions.] ''From Dr. Bryan Heit:'' "This study may interest some here. A lot of yeast evolution is driven by introgression - interspecies hybridization which gets "cleaned up" by back-crosses with one of the parental species (but leaving pieces of the other parental species genome behind). But it's always been a bit of a mystery of how these hybrids can back-cross, since these hybrids are usually unable to reproduce sexually. These scientists found a '''living''' ancestor of a hybrid between ''S. cerevisiae'' and ''S. paradoxus'' that gave rise to many modern ''S. cerevisiae'' strains, and may have figured out how it regained the ability to reproduce with its parental species <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/4055441394484044 Dr. Bryan Heit. Milk The Funk post on a new study that found a living ancestor of a hybrid between ''S. cerevisiae'' and ''S. paradoxus'' that gave rise to many modern ''S. cerevisiae'' strains. 11/12/2020.]</ref>."** [https://www.sciencedaily.com/releases/2019/03/190305153648.htm Modern beer yeast emerged from mix of European grape wine, Asian rice wine yeast, by Science Daily. The two explanations of beer yeast ancestry are: beer yeasts might have evolved from a mix of European wine strains and Asian fermentation strains during trade on the Silk Route, as well as an unknown ancestor. The second explanation is that European wine strains themselves descended from Asian strains (whether European wine strains desceneded descended from Asia or were developed in Europe has not been clear and needs more research).]
** [[Kveik#Recent_Yeast_Lab_Analysis_and_Commercial_Availability|Norwegian "kveik" yeast forms its own genetic group of yeast, indicating a subtree of the Beer 1 group.]]
** [https://www.nature.com/articles/s41559-019-0998-8 Fermentation innovation through complex hybridization of wild and domesticated yeasts] - Hittinger lab sequencing of commercial and homebrew strains of yeast, analysing analyzing their hybrid species makeup using WGS.
** [https://beer.suregork.com/?p=4112 BREWING YEAST FAMILY TREE (OCT 2019 UPDATE)] Kristoffer Krogerus' updated family tree including the Hittinger WGS data.
** [https://www.biorxiv.org/content/10.1101/2020.02.08.939314v2 "Domestication reprogrammed the budding yeast life cycle," De Chiara et al (2020).]
** Genome analysis of 1800 isolates from all ''Saccharomyces'' species by [https://www.nature.com/articles/s41467-023-36139-2 Peris et al. (2023)] found that domesticated strains of ''S. cerevisiae'' displayed a higher rate of admixture (occurs when distinct lineages mix to create new genetic lineages) <ref name=Peris_2023" />.
* Guinness yeast strains form their own mosaic (distinct genetic grouping) that is different than other Irish brewing strains (which are closely related to British brewing strains). Their closest related yeast is a Belgian ale strain that was used for "lagers" and was originally misidentified as lager yeast. The authors of the study that discovered this suggest that this Belgian strain originated from Dublin brewers. The two currently used Guinness yeast strains are very closely related to the original strains that were originally banked by Guinness: the 1903 Watling Laboratory Guinness yeast <ref>[https://www.nature.com/articles/s42003-023-05587-3 Kerruish, D.W.M., Cormican, P., Kenny, E.M. et al. The origins of the Guinness stout yeast. Commun Biol 7, 68 (2024). https://doi.org/10.1038/s42003-023-05587-3.]</ref>. See also [https://www.facebook.com/groups/MilkTheFunk/posts/7826465880714891/ this MTF post].
See also:
* YouTube presentation by Kevin Verstrepen:
: <youtube height="200" width="300">E6qBnBQuWF4</youtube>
* [http://masterbrewerspodcast.com/101-the-yeasts-of-tomorrow Stijn Mertens and Jan Steensels talk about their work on the MBAA podcast.]
* [https://www.ncbi.nlm.nih.gov/genome Genome searches] and [https://www.ncbi.nlm.nih.gov/Traces/study/? strain publication searches] (see [https://www.facebook.com/groups/MilkTheFunk/permalink/4506794029348776/?comment_id=4507353275959518 this example]).
* Media stories of "ancient yeast" supposedly being revived:
** [https://www.facebook.com/groups/MilkTheFunk/permalink/2934420516586143/ MTF discussion on a claim that a 4500 year old yeast was recovered from Egyptian pottery.]
* [https://www.biorxiv.org/content/10.1101/2020.06.26.166157v1.full Modern brewing yeasts continue to adapt to the modern brewing environment as the brewing methods change from yeast lab propagation and serial re-pitching: "Genomic stability and adaptation of beer brewing yeasts during serial repitching in the brewery".]
:<youtube height="200" width="300">sPHwItOxuK0</youtube>
* [https://www.facebook.com/groups/MilkTheFunk/permalink/4374738789220968/ MTF thread] by Dr. Bryan Heit provides a summary of [https://elifesciences.org/articles/63910 "Phenotypic and molecular evolution across 10,000 generations in laboratory budding yeast populations"]
====Killer Wine Yeast====
In ''Saccharomyces cerevisiae'', 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''. Rodriguez et al. (2011) reported that out of 1,114 strains of ''S. cerevisiae'' isolated from spontaneous wine fermentations, 38% of them were killer positive with most producing K2. Only 7% of produced the Klus toxin (no commercial wine yeast strains have been reported to produce the Klus toxin that we know of) <ref name="Rodriguez">[http://aem.asm.org/content/77/5/1822.long 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]</ref>. 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 <ref name="Rodriguez"></ref>. The activity of the toxin is greatest during the log phase of growth, and decays during the stationary phase of fermentation <ref name="Buyuksirit"></ref>. Generally, none of the toxins secreted by killer strains of ''Saccharomyces'' have been found to kill ''Brettanomyces'' <ref>[http://www.scielo.org.za/scielo.php?pid=S2224-79042015000100010&script=sci_arttext&tlng=pt Non-Saccharomyces killer toxins: Possible biocontrol agents against Brettanomyces in wine? S. Afr. J. Enol. Vitic. vol.36 n.1 Stellenbosch. 2015.]</ref>. One study from India reported that a wild ''S. cerevisiae'' strain caught from flowers killed another wild caught strain of ''Brettanoyces anomulus'', however, their methodology was not explicit and potentially not scientifically rigorous enough <ref>[http://nopr.niscair.res.in/handle/123456789/7735 Production and effect of killer toxin by Saccharomyces cerevisiae and Pichia kluyveri on sensitive yeasts and fungal pathogens. Dabhole, Madhusudan P, Joishy, K N. 2005.]</ref>. For example, this study did not use DNA fingerprinting to identify the wild yeast strains used in the study and instead relied on morphology and media selection, and they did not identify the type of toxin produced by the killer strain of wild ''S. cerevisiae''. They also reported that the ''B. anamulus'' strain did not ferment glucose, which is not typical for this species and indicates that it might have been misidentified.
Several strains of ''Saccharomyces eubayanus'' isolated from seeds from monkey puzzle trees in Patagonia, Argentina, were found to secrete a killer toxin that kills ''Brettanomyces'' and ''Pichia''. One strain was found to produce a lot of the toxin, which is called "SeKT". ''S. cerervisiae'' strains, including strains that are sensitive to the above toxins, are not sensitive to this toxin. Mazzucco et al. (2019) found that SeKT toxin produced by this one strain of ''S. eubaynus'' in a special growth medium designed to maximize the SeKT toxin production (WUJ medium, which is "ultrafiltered" apple and pear juice) inhibited a strain of ''B. bruxellensis'' to around 50% growth after 48 hours in a wine growth medium. It also inhibited ''Pichia guilliermondii'', ''Pichia manshurica'', and ''Pichia membranifaciens'' by 50-70%. Note that the toxin was applied directly to the ''Brettanomyces'' and ''Pichia'' species, and not in a co-fermentation setting. Since ''S. cerevisiae'' strains are not effected by the SeKT toxin, it has been proposed as a way to limit ''Brettanomyces'' and ''Pichia'' in wine fermentations <ref>[https://www.ncbi.nlm.nih.gov/pubmed/30671692?dopt=Abstract Production of a novel killer toxin from Saccharomyces eubayanus using agro-industrial waste and its application against wine spoilage yeasts. Mazzucco MB, Ganga MA, Sangorrín MP. 2019. DOI: 10.1007/s10482-019-01231-5.]</ref>.
Various other yeast species have the ability to produce toxins that effect a range of other yeasts (but generally not bacteria), including species from the genera ''Candida'', ''Cryptococcus'', ''Debaryomyces'', ''Hanseniaspora'', ''Hansenula'', ''Kluyveromyces'', ''Metschnikowia'', ''Pichia'', ''Ustilago'', ''Torulopsis'', ''Williopsis'', ''Zygosaccharomyces'', ''Aureobasidium'', ''Zygowilliopsis'', and ''Mrakia'' <ref name="Buyuksirit">[http://waset.org/publications/9999528/antimicrobial-agents-produced-by-yeasts Antimicrobial Agents Produced by Yeasts. T. Buyuksirit, H. Kuleasan. 2014.]</ref><ref name="Stewart_2018" />. For example, strains of the yeast species ''Candida pyralidae'' <ref name="Buyuksirit"></ref>, ''Wickerhamomyces anomalus'', ''Kluyveromyces wickeramii'', ''Torulaspora delbrueckii'' and ''Pichia membranifaciens'' have been found to produce toxin that inhibits ''Brettanomyces'' <ref name="Ciani_2016">[https://www.researchgate.net/publication/301581233_Yeast_Interactions_in_Inoculated_Wine_Fermentation Yeast Interactions in Inoculated Wine Fermentation. Maurizio Ciani, Angela Capece, Francesca Comitini, Laura Canonico, Gabriella Siesto and Patrizia Romano. 2016.]</ref><ref>[https://www.mdpi.com/1422-0067/24/2/1309 Agarbati A, Ciani M, Esin S, Agnolucci M, Marcheggiani F, Tiano L, Comitini F. Comparative Zymocidial Effect of Three Different Killer Toxins against Brettanomyces bruxellensis Spoilage Yeasts. International Journal of Molecular Sciences. 2023; 24(2):1309. https://doi.org/10.3390/ijms24021309 .]</ref>. In addition, the toxin produced by ''Wickerhamomyces anomalus'' and ''Williopsis markii'' have been found to inhibit a wide range of spoilage and pathogenic fungi <ref name="Hatoum2012"></ref>. 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 <ref name="Buyuksirit"></ref>. Strains of ''Torulaspora delbrueckii'' have been shown to kill killer strains of ''S. cerevisae'' (wine strains), as well as to kill ''Pichia'' species <ref name="Ciani_2016"></ref>. The occurrence of killer strains of yeast in the wild is also wide spread. For example, out of 210 yeasts from various genera isolated from molasses, 13 of them were killer strains. Out of 1,000 isolates of various ''Candida'' species isolated from human skin, 52 were killer strains. Out of 65 strains of various yeasts isolated from fermented foods, soil samples, and spoiled fruits/vegetables, 12 were killer strains <ref name="Bajaj_2017" />. It has been hypothesized that toxin production is ubiquitous throughout nearly all genera of yeast; the more studies that have been done on a particular genus of yeast, the more likely it is that toxin production has been found by species and strains within that genus. Yeasts that produce toxins have been found on every continent and in every natural habitat of yeast, including leaf surfaces, leaf litter, tree slime fluxes, fruits, cactus stems and cladodes, insect guts, mammal feces, leaf-cutting ant nests, lake water, ocean sediment, soil, wine, bakeries, and dairy products <ref name="Boynton_2019" />.
Scientists have used genetic modification to create ''S. cerevisiae'' strains that produce various killer toxins that can assist in completing fermentation in the baking, wine, distillation, and beer making processes. These yeasts are able to inhibit undesired yeast contaminants, preventing various off-flavors and other unwanted characteristics in the finished products. Ale and lager strains that have been modified to release these toxins have reportedly retained the positive fermentation and flavor characteristics of the original strains <ref name="Bajaj_2017" />. Branco et al. (2017 and 2019) discovered several strains of ''S. cerevisiae'' that excrete a biocin toxin that is active against several other genera of yeast, including ''Brettanomyces bruxellensis''. The toxin is composed of peptides derived from the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH), which is a protein that serves many different roles in different species of microbes and animals. This toxin is produced by some strains of ''S. cerevisiae'' as they enter the stationary phase after primary fermentation. However, the amount of the toxin needed to inhibit ''B. bruxellensis'' was 10 times the amount that is produced naturally during fermentation. The researchers later genetically modified a strain of ''S. cerevisiae'' to over-produce the toxin, which they named "saccharomycin", at levels required to completely inhibit ''B. bruxellensis'' when co-pitched at a 1:1 ratio (10^5 cells/ml for both). This toxin was also reported to be highly active against ''Hanseniaspora guilliermondii'', ''Kluyveromyces marxianus'', ''Lactobacillus thermotolerans'' (inhibited at 250 μg/ml of toxin), while inhibition of ''Torulaspora delbrueckii'' and ''B. bruxellensis'' required very high amounts of the toxin (500 μg/ml and 1000-2000 μg/ml) <ref>[https://link.springer.com/article/10.1007%2Fs00253-016-7755-6 Antimicrobial properties and death-inducing mechanisms of saccharomycin, a biocide secreted by Saccharomyces cerevisiae. Patrícia Branco, Diana Francisco, Margarida Monteiro, Maria Gabriela Almeida, Jorge Caldeira, Nils Arneborg, Catarina Prista, Helena Albergaria. 2017. DOI: 10.1007/s00253-016-7755-6.]</ref><ref>[https://link.springer.com/article/10.1007/s00253-019-09657-7 Biocontrol of Brettanomyces/Dekkera bruxellensis in alcoholic fermentations using saccharomycin-overproducing Saccharomyces cerevisiae strains. Patrícia Branco, Farzana Sabir, Mário Diniz, Luísa Carvalho, Helena Albergaria, Catarina Prista. 2019.]</ref>. They later demonstrated that using 1.0 mg/mL of saccharomycin with 25 mg/L of SO<sub>2</sub> in grape must fermentation completely eliminated ''B. bruxellensis'' <ref>[https://www.mdpi.com/2076-2607/9/12/2528#cite Branco P, Coutinho R, Malfeito-Ferreira M, Prista C, Albergaria H. Wine Spoilage Control: Impact of Saccharomycin on Brettanomyces bruxellensis and Its Conjugated Effect with Sulfur Dioxide. Microorganisms. 2021; 9(12):2528. https://doi.org/10.3390/microorganisms9122528]</ref>.
See also:
* [https://www.facebook.com/groups/MilkTheFunk/permalink/4640413255986852/?comment_id=4640439825984195 None of the wine yeast strains from White Labs are killer positive, according to Kara Taylor, White Labs Senior Lab Manager.]
* [https://www.facebook.com/groups/MilkTheFunk/permalink/2202753476419521/?comment_id=2202936416401227&comment_tracking=%7B%22tn%22%3A%22R0%22%7D Bryan Heit's simple method for testing for killer sensitivity using nothing more than agar plates.]
* [https://www.homebrewtalk.com//forum/threads/from-the-lab-wine-yeast-pof-and-killer-status.648095/ List of killer strains as well as phenol production (4VG and 4VP) in various wine yeasts, compiled from a scientific study Hisamoto et al. (2010).]
* For the implications of this on re-yeasting beer with wine yeast at packaging, see the [[Packaging#Re-yeasting|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_Inoculation#Potential_Problems_and_Issues|Commercial Sour Beer Dregs]].
* [http://www.babblebelt.com/newboard/thread.html?tid=1108752780&th=1275037001 Shea Comfort notes on wine yeast on the BBB.]
* [https://byo.com/article/brewing-with-wine-yeast/ "Brewing With Wine Yeasts" by Michael Tonsmeire"]. See also [https://www.facebook.com/groups/MilkTheFunk/permalink/1392709617423915/ Dara McMains's MTF thread on beer fermentation with wine yeast and ''Brettanomyces''].
* [https://www.asianbeernetwork.com/brewing-beer-with-wine-yeast "Brewing Beer with Wine Yeast," by Neil Playfoot, Asian Beer Network.]
To do: https://www.researchgate.net/publication/317177883_Biology_of_Killer_Yeast_and_Technological_Implications
=====Using Killer Yeast to Inhibit Diastatic Yeast=====
* [https://brewing.confex.com/brewing/2020/meetingapp.cgi/Paper/1383 WBC 2020 Presentation "Can we rescue Beer infected with Diastaticus during fermentation: A profile in killer yeast and the effect of co-fermentation on the superattenuative characteristics of diastaticus."]
* [https://www.masterbrewerspodcast.com/193 MBAA Podcast episode 193 with Nicholas Ketchum, "Could beer infected with diastaticus be rescued by killer yeast?"]
* [https://www.facebook.com/groups/MilkTheFunk/permalink/4220596401301875 MTF post on using CBC-1 killer positive to limit primary yeast.]
=====Autotoxin=====
- https://journals.plos.org/plosbiology/article?id=10.1371%252Fjournal.pbio.3001844
====Diastatic strains of ''Saccharomyces cerevisiae''====
</blockquote>
Diastatic strains of ''Saccharomyces cerevisiae'', historically designated as a variant of ''S. cerevisiae'' (''Saccharomyces cerevisiae'' var. ''diastaticus''), is a group of ''S. cerevisiae'' strains 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. The variant based nomenclature has been called into question (classifying it as a true variant based on one phenotype is not typical in microbiology), and terms like "''STA1+'' strains of ''S. cerevisiae''" or "diastatic ''cerevisiae''" have been proposed as a more scientifically correct designation <ref name="Omega_diastaticus_2020">[https://omegayeast.com/news/improved-functional-assays-and-risk-assessment-for-sta-strains-of-saccharomyces-cerevisiae Improved Functional Assays and Risk Assessment for STA+ Strains of Saccharomyces cerevisiae. Laura T. Burns, Christine D. Sislak, Nathan L. Gibbon, Nicole R. Saylor, Marete R. Seymour, Lance M. Shaner, and Patrick A. Gibney. 2020. Awaiting peer review and publication.]</ref><ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/3308119659216225/?comment_id=3308312722530252&reply_comment_id=3308849332476591 Kristoffer Krogerus. Milk The Funk Facebook group post on diastatic ''cerevisiae'' nomenclature. 02/27/2020.]</ref><ref name="krogerus_diastatic_2020">[https://link.springer.com/article/10.1007/s00253-020-10531-0 A re-evaluation of diastatic Saccharomyces cerevisiae strains and their role in brewing. Kristoffer Krogerus and Brian Gibson. Applied Microbiology and Biotechnology (2020). DOI: https://doi.org/10.1007/s00253-020-10531-0.]</ref>. These strains generally do not produce flavors that are considered unpleasant. For example, acetaldehyde and sulfur dioxide are produced in very low amounts compared to other brewing strains. With the exception of a couple of few strains, such as the "Sacch Trois" strain, almost all most diastatic ''cerevisiae'' strains also produce phenols (POF+), which are considered an off-flavor flavors in many beer stylesother than Belgian ale styles and German Hefeweizen (there is no genetic link between POF+ and STA1 genes, and the link may just be coincidental due to human selection). Most strains also produced significant amounts of isoamyl acetate (banana ester) and other fruity esters, making them taste very similar to German wheat strains. A small number of strains also produce above flavor threshold levels of diacetyl <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>. This variant 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 contamination 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>.
''STA1+'' strains 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'' gene, which is a fusion of two other genes that are present separately in all ''S. cerevisiae'' yeasts, ''FLO11'' and ''SGA1'' (the ''STA2'' and ''STA3'' genes are the same as ''STA1''; they were initially found on different chromosomes and so they received different names, but they are all the same gene <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2697088176986046/?comment_id=2697419373619593&reply_comment_id=2698451940183003&comment_tracking=%7B%22tn%22%3A%22R%22%7D Kristoffer Krogerus. Milk The Funk Facebook thread post on the significance of STA2 and STA3 genes in diastatic strains. 06/01/2019.]</ref>). Not all strains containing one of these genes produce 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>. It has been reported by some microbiologists that most brewing strains that contain the ''STA1'' gene 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). A study that surveyed 18 strains of ''S. cerevisiae'' that contain the ''STA1'' gene found that only one was not able to ferment dextrins <ref name="Meier-Dörnberg_2018" />. Richard Preiss has also reported that WLP351 has the ''STA1'' gene, but is not able to ferment dextrins <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1888017211226484/?comment_id=2013050695389801&reply_comment_id=2013355312026006&comment_tracking=%7B%22tn%22%3A%22R9%22%7D Richard Preiss. Milk The Funk Facebook group thread on diastatic strains that do not ferment dextrins. March 2018.]</ref>. Krogerus et al. (2019) discovered that a region of 1162 base pairs just upstream of the ''STA1'' gene called "a promoter gene" is missing in strains that test positive for the ''STA1'' gene but do not test positive for fermenting starches, dextrins, or secreting the enzyme. They were able to demonstrate that this promoter gene region is needed for the ''STA1'' gene to become expressed. They also discovered that ''STA1'' gene is found in the Beer 2 group of yeast (see [[Saccharomyces#History_of_Domestication|History of Domestication]] above), and wild ''S. cerevisiae'' strains do not carry the ''STA1'' gene. Coincidentally, Beer 2 yeast strains lack the genes that the Beer 1 yeast strains do for fermenting maltotriose, yet Beer 2 yeasts ferment maltotriose just fine; it was discovered by Krogerus et al. (2019) that the ''STA1'' gene allows the Beer 2 yeasts to ferment maltotriose (although this exact mechanism is not known yet). It was proposed that the ''STA1'' gene evolved in the Beer 2 yeast strains as a means to take advantage of grain fermentation as an evolutionary advantage, and the existence of strains that are missing the promoter gene could be because humans later started selecting for strains that didn't dry the beer out too much <ref name="krogarus_2019">[https://link.springer.com/article/10.1007/s00253-019-10021-y A deletion in the ''STA1'' promoter determines maltotriose and starch utilization in ''STA1+'' Saccharomyces cerevisiae strains. Kristoffer Krogerus, Frederico Magalhães, Joosu Kuivanen, Brian Gibson. 2019. DOI: https://doi.org/10.1101/654681.]</ref>. For more details on the Krogerus et al. (2019) study, see [http://beer.suregork.com/?p=4068 this Suregork Loves Beer blog post] and [https://www.facebook.com/groups/MilkTheFunk/permalink/2697088176986046/ this MTF thread posted by Kristoffer Krogerus].
This yeast can 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 ''STA1+'' strains of ''S. cerevisiae''. Additionally, the default level of CuSO<sub>4</sub> which is ~550 ppm (this can vary depending on manufacturer) can inhibit some strains of diastatic ''cerevisiae''; Wade Begrow of Founders Brewing Co. recommends diluting the LCSM media with a basic malt media so that the CuSO<sub>4</sub> reaches around 200 ppm, or using LCSM plates modified with a gradient of CuSO<sub>4</sub> <ref name="Begrow_MBAA" /> (~22 mins in). Adding p-coumaric acid or other cinnamic acids to the LCSM agar media which can then test for POF+ yeast and then confirmed for the presence of phenols via a gas chromatography or some other method can also be used to indicate that a yeast might be ''STA1+'' since most strains produce phenols from these cinnamic acids <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2149139905114212/?comment_id=2150763631618506&reply_comment_id=2158975484130654&comment_tracking=%7B%22tn%22%3A%22R0%22%7D Shawn Savuto and linked references. Milk The Funk Facebook book post on POF+ correlation with diastatic ''cerevisiae''. July 2018.]</ref> (see also [https://www.facebook.com/groups/MilkTheFunk/permalink/1903290776365794/ this MTF thread] on using cinnamic acids to identify phenolic off flavor strains).
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]]). A recent study used agar plates with 15 g/L<sup>-1</sup> of starch as the only nutrient with 40 mg/L<sup>-1</sup> bromophenol blue in anaerobic conditions to detect the fermentation of starch (a pH drop from 5.2 to 4.6-3.0 will change the color of the agar plate to blue/violet). For some of the slower growing strains, 14 days were required to verify that they were ''STA1+'' while other strains grew as quickly as two days and most strains grew after five days. The yeast cells had to be thoroughly washed of all other carbohydrate material and starved in order to avoid false positives. Using dextrin agar plates instead of starch also led to false positives <ref name="Meier-Dörnberg_2018" />. This starch media has been recommended by Richard Preiss from [[Escarpment Laboratories]] and Justin Amaral from [[Mainiacal Yeast]] <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2149139905114212/?comment_id=2150763631618506&comment_tracking=%7B%22tn%22%3A%22R%22%7D Richard Preiss and Justin Amaral. Milk The Funk Facebook thread on plate media for diastatic ''cerevisiae''. 06/26/2018.]</ref>. Note that diastatic ''S. cerevisiae'' cells look the same under a microscope as regular ''S. cerevisiae'', so cell morphology is not an effective way to identify ''STA1+'' strains <ref name="Begrow_MBAA">[https://www.mbaa.com/education/webinars/Pages/webcast.aspx?vid=diastaticus Wade Begrow. "S. cerevisiae var. diasttaicus". MBAA webinar. July 2018.]</ref> (~8 minutes in). Other methods of detection include using a Durham tube/fermentation tube test to see if the beer produces CO<sup>2</sup> after fermentation, although this method does not identify the cause of the additional fermentation <ref name="Begrow_MBAA" /> (~18 mins in). More recently, Krogerus et al. (2019) developed more precise PCR primers to detect ''STA1'' active, ''STA1'' non-active, and non-''STA1'' based on their discovered role of an ''STA1'' promoter called ''1162 bp'' that is required for the ''STA1'' gene to be effective at producing the glucoamylase enzyme, however, PCR and qPCR have limited detection rates of 10<sup>-4</sup> and 10<sup>-5</sup> cells (see [http://beer.suregork.com/?p=4068 this Suregork Loves Beer blog post] and [https://www.facebook.com/groups/MilkTheFunk/permalink/2697088176986046/ this MTF thread posted by Kristoffer Krogerus]).
Detection of ''STA1+'' strains of ''S. cerevisiae'' as a contaminant can be difficult. While using PCR to detect the ''STA1'' gene and the promoter gene, the presence of the promoter gene alone does not completely explain the wide variance of diastatic power between strains. Additionally, PCR genotyping is sucseptable to user error or DNA detection from dead cells. Detection of the presence of starch degrading enzymes can come from other contaminants such as ''Brettanomyces'' <ref name="Omega_diastaticus_2020" />. Some agar media products and even starch/dextrin materials have been suspected to contain small amounts of glucose or other simple sugar contaminants that can support the growth of non-diastatic yeasts <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/3308119659216225/ Lance Shaner and Joshua Mayers. Milk The Funk Facebook thread on Omega Yeast's STA1+ detection methods. 03/04/2020.]</ref>. [[Omega Yeast Labs]] reported that a slight alteration to the classic LCYM media recipe had significantly more reliable detection than classic LCYM and the proprietary Weber diastatic agar for all ''STA1+'' strains in Omega's collection, including detecting slow growing strains within 2-3 days and strains with the non-active promoter genes as per Krogerus et al (2019) and limited false positives. See [[Laboratory_Techniques#Saccharomyces|''Saccharomyces'' agar plates]] for the recipe and [https://www.facebook.com/groups/MilkTheFunk/permalink/2874530432575152/ this MTF thread] by Laura Burns from Omega Yeast Labs, as well as their [https://omegayeast.com/news/improved-functional-assays-and-risk-assessment-for-sta-strains-of-saccharomyces-cerevisiae associated comprehensive write up peer reviewed study on recommended detection methods )] <ref>[https://www.tandfonline.com/doi/full/10.1080/03610470.2020.1796175 Laura T. Burns, Christine D. Sislak, Nathan L. Gibbon, Nicole R. Saylor, Marete R. Seymour, Lance M. Shaner & Patrick A. Gibney (pending peer review 2020) Improved Functional Assays and potential publication)Risk Assessment for STA1+ Strains of Saccharomyces cerevisiae, Journal of the American Society of Brewing Chemists, DOI: 10.1080/03610470.2020.1796175 .]</ref>. A summary of the Omega Yeast Lab detection methodology findings by Lance Shaner is available [https://www.facebook.com/groups/MilkTheFunk/permalink/3308119659216225/ here on MTF]. Escarpment Labs built upon the work by Burns et al. and developed a modified version of the Omega LCYM, and they reported it to have less false positives for non-diastatic strains and it has reportedly been used for growing beer strains of ''Brettanomyces'' and ''Pichia''. See the [[Laboratory_Techniques#Saccharomyces|Escarpment SCCM media]]. In 2022, Ida Uotila and Kristoffer Krogerus developed a simple detection technique that only requires basic lab equipment (pipettes, centrifuge, and heat block), gives results from beer or yeast samples in 75 minutes, and with accuracy as good as traditional PCR-based methods. The test result can be visualized on a lateral flow strip. For more information, see [https://www.biorxiv.org/content/10.1101/2022.11.23.517627v1 their published paper] ([https://www.facebook.com/groups/MilkTheFunk/posts/6360775983950562 associated MTF thread]).
=====Commercial Strains=====
* [http://masterbrewerspodcast.com/068-diastaticus-part-1 MBAA Podcast on diastaticus Part 1] and [http://masterbrewerspodcast.com/069-diastaticus-part-2 Part 2]. Also [https://www.masterbrewerspodcast.com/152 Using FPDM media from Dr. Farber vs Weber, and issues with media getting too old after a day or two].
* [https://www.mbaa.com/education/webinars/Pages/webcast.aspx?vid=diastaticus MBAA webinar by Wade Begrow (free for MBAA members, $50 for non-members).]
* [https://www.masterbrewerspodcast.com/193 MBAA Podcast Episode 193, "Killer Yeast" with Nicholas Ketchum on using killer yeast strains to kill diastatic yeast.]
* [https://brulosophy.com/podcasts/the-bru-lab/ Bru Lab Podcast, Episode 021 | Detection and Risk Assessment of Diastatic Yeast w/ Dr. Laura Burns.]
====''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'' <ref>[https://en.wikipedia.org/wiki/Saccharomyces_boulardii ''Saccharomyces boulardii''. Wikipedia. Retrieved 12/07/2017.]</ref>. This strain is sold by [[East Coast Yeast]] in their ECY03 Farmhouse Blend and [[Bootleg Biology]] as their "Chardonnay" strain <ref>[https://bootlegbiology.com/product/chardonnay "Chardonnay (S. cerevisiae boulardii)". Bootleg Biology website. Retrieved 11/20/2019.]</ref>.
====Genetic Engineering====
* [https://www.lallemandbrewing.com/en/united-states/product-details/sourvisiae Lallemand SOURVISIAE®] is GE California ale yeast based strain that produces lactic acid as a by product of fermentation. See also [http://suigenerisbrewing.com/index.php/2021/02/19/diving-deep-in-to-sourvisiae/ "Diving Deep In To Sourvisiae" by Dr. bryan Heit].
* [https://link.springer.com/article/10.1007/s00253-021-11626-y Efficient breeding of industrial brewing yeast strains using CRISPR/Cas9-aided mating-type switching.]
===''S. jurei''===
Newly discovered ''S. jurei'' was screened for use in beer, as well as hybrids between two strains of ''S. jurei'' and two strains of ''S. cerevisiae'' (Omega Labs OYL200 "Tropical IPA" and OYL500 Saisonstein). The hybrids were non-GMO type hybrids (natural mating). As expected, the hybrids were better at fermentation in wort (better utilization of maltose and maltotriose). The hybrids were reported to be "tropical and floral" from esters characterized by a combination of both parents, and one of the hybrids appeared to have lost the ability to produce phenols (4-vinyl guaiacol; clove) from the ''S. jurei'' parent <ref>[https://www.biorxiv.org/content/10.1101/2021.01.08.425916v1.full.pdf Biotechnological exploitation of Saccharomyces jureiand its hybrids in craft beer fermentation uncovers new aroma combinations. Konstantina Giannakou, Federico Visinoni, Penghan Zhang, Nishan Nathoo, Paul Jones, Mark Cotterrell, Urska Vrhovsek, and Daniela Delneri. 2020. doi: https://doi.org/10.1101/2021.01.08.425916 .]</ref>.
===''S. ludwigii''===
* [https://link.springer.com/article/10.1007/s00217-020-03572-2 Brewing potential of the wild yeast species ''Saccharomyces paradoxus''.]
===''S.eubayanus''===
[[File:Mardones 2020 Fig1C.JPG|thumb|300px|Utilization of maltose by 10 strains of ''S. eubayanus''; higher utilization corresponds with higher ethanol production. Figure 1C from [https://sfamjournals.onlinelibrary.wiley.com/doi/full/10.1111/1751-7915.13545 Mardones et al (2020)]. Uploaded with permission from Kristoffer Krogerus.]]
[[File:Mardones 2020 Fig1D.JPG|thumb|300px|Volatile compound production of interest in beer by 10 strains of ''S. eubayanus''. Figure 1D from [https://sfamjournals.onlinelibrary.wiley.com/doi/full/10.1111/1751-7915.13545 Mardones et al (2020)]. Uploaded with permission from Kristoffer Krogerus.]]
''S.eubayanus'' is one of the probable parents of lager yeast (''S. pastorianus'') via the hybridisation with ''S. cerevisiae'' <ref name="libkind_2011"></ref><ref name="bing_2014"></ref>.
It was first isolated and described in 2011 growing within ''Nothofagus'' trees in Patagonia, Argentina. Since then, strains of this species have also been found in cold regions across the globe, including Tibet, China, the United States, Chile, and New Zealand. It has also been isolated from the wild in Ireland <ref>[https://academic.oup.com/femsyr/article/22/1/foac053/6874782 Sean A Bergin, Stephen Allen, Conor Hession, Eoin Ó Cinnéide, Adam Ryan, Kevin P Byrne, Tadhg Ó Cróinín, Kenneth H Wolfe, Geraldine Butler, Identification of European isolates of the lager yeast parent Saccharomyces eubayanus, FEMS Yeast Research, Volume 22, Issue 1, 2022, foac053, https://doi.org/10.1093/femsyr/foac053.]</ref>. ''S. eubayanus'' has been described as being cold-tolerant, and can grow between 4–25°C. It has been suggested that this trait was inherited by lager yeast.
Although only a small number of strains have been collected from the wild by scientists, ''S. eubayanus'' has a wide range of genetic diversity between different strains. Some strains show potential for brewing purposes, which is primarily characterized by how well they ferment maltose. [https://sfamjournals.onlinelibrary.wiley.com/doi/full/10.1111/1751-7915.13545 Mardones et al. (2020)] evaluated 10 strains of ''S. eubayanus'' and their potential for fermenting wort. Four of the strains were isolated from Chile, four from Patagonia, one from Argentina, and one from New Zealand. All of the strains efficiently fermented glucose and fructose, while none fermented maltotriose. Maltose utilization varied greatly across all of the strains with the Argentinian strain (CBS-12357) utilizing maltose the most and producing the most ethanol. Overall, there was no correlation to how well strains fermented maltose based on what country they were from. There was also a wide range of esters, higher alcohols, and carbonyl compounds produced by the different strains. For example, two of the strains of Patagonia (CL465.1 and CL450.1) produced some higher alcohols and acetate esters like 2-phenyethyl acetate (rose, honey) and 3-methylbutyl acetate (banana), while other strains (Argentinian strain CBS-12357 and Chilean strain CL216.1) produced more ethyl octanoate and ethyl decanoate (fruity and apple-like). Nearly half the strains produced very low levels of all of the compounds measured. Most strains produced insignificant levels of acetaldehyde, except for two of the Chilean strains <ref name="Mardones_2020">[https://sfamjournals.onlinelibrary.wiley.com/doi/full/10.1111/1751-7915.13545 Molecular profiling of beer wort fermentation diversity across natural Saccharomyces eubayanus isolates. Wladimir Mardones, Carlos A. Villarroel, Kristoffer Krogerus, Sebastian M. Tapia, Kamila Urbina, Christian I. Oporto, Samuel O’Donnell, Romain Minebois, Roberto Nespolo, Gilles Fischer, Amparo Querol, Brian Gibson, Francisco A. Cubillos. 2020. DOI: https://doi.org/10.1111/1751-7915.13545.]</ref>.
Commonly known as lager yeast to brewers, this yeast is a hybrid of ''S. eubayanus'' and ''S. cerevisiae'' <ref name="wikipedia_cereisiae" />. ''S. pastorianus'' is named after the first description by Max Reess in 1870 following his work with German breweries utilizing bottom-fermenting lager yeast, naming it originally after Louis Pasteur.
For a long time the origins of the hybrid were unknown and were postulated to be a hybrid between ''S. cerevisiae'' and ''S.uvarum'', or ''S. cerevisiae'' and ''S.bayanus''. Recent work eg. Libkind et al 2011 proved that the hybridisation was between ''S. eubayanus'', which had been recently found in South America and ''S. cerevisiae'' <ref name="libkind_2011" />. Further work points to a Tibetan lineage of ''S.eubayanus'' being the most likely from those discovered in the wild so far <ref name="bing_2014" /> (see also [https://www.facebook.com/groups/MilkTheFunk/posts/6399366356758191/?comment_id=6399963343365159 this MTF post]). It is hypothesized that the hybridization event occurred in a Bavarian brewery (Hofbräuhaus in Munich has been proposed as the most likely site for the hybridization event) in the 16th century by the chance interaction of ''S. eubayanus'' with ale yeast; however, an alternative hypothesis is that bottom-fermentation with ''S. eubayanus'' was in practice before lager yeast was created <ref>[https://academic.oup.com/femsyr/article/doi/10.1093/femsyr/foad023/7142826 Mathias Hutzler, John P Morrissey, Andreas Laus, Franz Meussdoerffer, Martin Zarnkow, A new hypothesis for the origin of the lager yeast Saccharomyces pastorianus, FEMS Yeast Research, Volume 23, 2023, foad023, https://doi.org/10.1093/femsyr/foad023.]</ref>.
This species is separated into two main lineages, "Saaz" and "Frohberg". The two lineages are believed to have descended from different hybridization events between ''S. eubayanus'' and ''S. cerevisiae''. The two lineages also have different genetic structure, with Frohberg types having two copies of each of the ''S. eubayanus'' and ''S. cerevisiae'' chromosomes (triploid), and Saaz types having one copy of the ''S. cerevisiae'' chromosomes and two copies of the ''S. eubayanus'' chromosomes (allotetraploid) <ref><[https://www.ncbi.nlm.nih.gov/pubmed/24578374 Genome sequence of Saccharomyces carlsbergensis, the world's first pure culture lager yeast. Walther A, Hesselbart A, Wendland J. 2014. DOI: 10.1534/g3.113.010090.]</ref>
[https://www.whitelabs.com/yeast-bank/wlp051-california-v-ale-yeast WLP051 California V Ale] yeast is also ''S. pastorianus''. Recent gene sequencing / PCR work has led to it being re-classified as a ''S. pastorianus'' yeast, though it has been used successfully for American-style Ale production.
Laboratory hybridization between different strains of ''S. cerevisiae'' and ''S. eubayamus'' strains from Patagonia has created new lager strains that have better fitness under fermentation, better maltotriose/maltose utilization, and fermentation capacity. These new strains offer more options to brewers who want to brew with lager yeast <ref>[https://www.biorxiv.org/content/10.1101/2024.01.29.577692v1 Wild Patagonian yeast improve the evolutionary potential of novel interspecific hybrid strains for Lager brewing. Jennifer Molinet, Juan P. Navarrete, Carlos A. Villarroel, Pablo Villarreal, Felipe I. Sandoval, Roberto F. Nespolo, Rike Stelkens, Francisco A. Cubillos. bioRxiv 2024.01.29.577692; doi: https://doi.org/10.1101/2024.01.29.577692.]</ref>.
See also:
* [https://www.crowdcast.io/e/escarpment-labs-fermentation-innovation Kristoffer Krogerus presentation on the genetics and evolution of lager yeast, hosted by Escarpment Laboratories, 4/20/2020.]
* [https://phys.org/news/2019-12-pilsner-yeast-strains-ancestor.amp "All pilsner yeast strains originate from a single yeast ancestor," by Delft University of Technology], summarizing the study by [https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-019-6263-3 Salazar et al. (2019)].
* [https://www.facebook.com/groups/MilkTheFunk/posts/4987612867933554/ MTF thread by Kristoffer Krogerus on how to use tetraploid interspecific hybrids to produce viable spores for designed lager yeast strain development, with a link to his peer reviewed article, 09/17/2021.]
* [https://www.crowdcast.io/c/lager-brewers-yeast-origins "Yeast Research and Scaling Secrets," interview with Dan Carey by Doug Piper.]
==In Fermentation==
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 <ref>[https://www.quantamagazine.org/20151103-snowflake-yeast-multicellularity/ "Life’s Secrets Sought in a Snowflake". Emily Singer. Quantum Magazine. 11/03/2015. Retrieved 12/27/2016.]</ref>). 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 <ref>[http://www.sciencedirect.com/science/article/pii/S1096717616301756 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.]</ref><ref>[http://www.nature.com/articles/ncomms7102 Origins of multicellular evolvability in snowflake yeast. William C. Ratcliff, Johnathon D. Fankhauser, David W. Rogers, Duncan Greig & Michael Travisano. 2015.]</ref>.
<!-- <youtube>UiWsVQwtidE</youtube> video made private-->
See also:
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===[[Bootleg Biology]]/[[Spot Yeast]]===
{| class="wikitable sortable"
|-
|-
| 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”.
|-
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===[[Community Cultures Yeast Lab]]===
{| class="wikitable sortable"
|-
! Name !! Source !! Attenuation !! Flocculation !! Temp°F !! Notes
|-
| TCL21 Ocotillo || Ocotillo plant in Big Bend, Texas || 86-91 || High || 69-74 || Suggested Use: Saison, Belgians, Farmhouse ales, Cider, Braggot, and wine. Determined to be a [[Saccharomyces#Diastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces bayanus'']]. Also POF+.
|-
| TCL22 Yucca || Torrey Yucca plant in Texas || 73-78 || Low || 68-72 || Determined to be a [[Saccharomyces#Diastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces bayanus'']]. POF+. Suggested Use: Witbier, Belgian Blond, Hefeweizen, Kristalweizen, Barrel aged beers.
|-
| TCL32 Chisos || Chisos Mountains, Texas || 86-91 || Low || 65-72 || Determined to be a [[Saccharomyces#Diastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces bayanus'']]. POF+. Suggested Use: Tripel, Belgians, Dubbels, Siason, Witbier, and farmhouse ales.
|-
| TCL25 Prickly Pear Blend || Big Bend, Texas || 73-80 || Med || 67-73 || Contains two strains of ''S. cerevisiae''. Determined to be a [[Saccharomyces#Diastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'']]. POF+. Suggested Use: American Pale Ale, IPAs, English pales, Hopped Sour (bacteria not provided), Gose.
|-
| TCL34 The Window || Prickly Pear Fruit in Big Bend, Texas || 70-75 || Med/High || 66-72 || Determined to be a [[Saccharomyces#Diastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'']]. POF+. Suggested Use: Belgians, Weizens, Trappist ale, Dubbels, German ales, and Saisons.
|-
| TCL31 The Falls || Columbine in Cattail Falls, Texas || 70-75 || Low || 62-72 || Determined to be a [[Saccharomyces#Diastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces bayanus'']]. POF+. Suggested Use: Witbier, Sour Witbier, Apricot Witbier, Citrus Wit, Hefeweizen, Belgian Ales, Dubbels, Trappist, Trippel, Saisons.
|-
| TCL24 Buttercup || Rio Grande River, Texas || 73-85 || High || 66-71 || Determined to be a [[Saccharomyces#Diastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'']]. POF+. Suggested Use: Belgians, Barley wine, Winterale, Scotch ale, Heavy Ales, Stouts, Porters.
|-
| TCLH1 Swallowtail || Swallowtail butterfly, Texas || 76-81 || Med/Low || 69-75 || Determined to be a [[Saccharomyces#Diastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'']]. POF+.
|-
| TCL38 El Monte Manor || San Antonio, Texas || 87-92 || Med || 66-72 || STA1 negative and POF+ strain of ''S. cerevisiae''. Suggested Use: IPA, Belgian Saison, Brett Saison, Nordic Ales, Altbier, Tripel, Belgian Blonde.
|-
| TCLJ1 Cenote Sac Actun || Cenote Sac Actun (fresh water cave), Texas || 89-94 || Med || 68-72 || Determined to be a [[Saccharomyces#Diastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'']]. POF+. Suggested Use: East Coast IPA, New England IPA, English Ales, Irish Red Ale, Brown Ales.
|-
|}
|-
| ECY14 Saison Single || Single Strain || 76-78 || || 75-82 || Smooth, full farmhouse character with mild esters reminiscent of apple pie spice
|-
| ECY46 Farmhouse 2 || || 80-84 || || 76-82 || An American farmhouse isolate (''Saccharomyces cerevisae'' / ''boulardii'') producing a pleasant tartness quickly upon fermentation (pH 4.0 - 4.1). Expect high attenuation, slight citrus esters and tartness <ref>[http://www.eastcoastyeast.com/ale---lager-yeast.html East Coast Yeast website. "Ale & Lager Yeast" page. Retrieved 03/27/2021.]</ref>.
|-
|}
|-
| 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% <ref name="escarpment_strains" />.
|-
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===[[Fermentis]]===
{| class="wikitable sortable"
|-
! Name !! Lab !! Source !! Attenuation !! Flocculation !! Temp°F !! Notes
|-
| [https://fermentis.com/en/fermentation-solutions/you-create-beer/safale-t-58/ SafAle™ 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.
|-
| [https://fermentis.com/en/fermentation-solutions/you-create-beer/safale-be-256/ SafAle™ 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.
|-
| [https://fermentis.com/en/fermentation-solutions/you-create-beer/safale-be-134/ 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 a [[Saccharomyces#Diastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'']] <ref>[http://fermentis.com/wp-content/uploads/2018/02/SafAle-BE-134_Rev2.pdf Fermentis BE-134 Spec Sheet. Retrieved 02/10/2018.]</ref><ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1890957430932462/ Private email correspondence with a Fermentis representative by Jeremy Johns; email forwarded to Dan Pixley for verification. 11/21/2017.]</ref>.
|-
| [https://fermentis.com/en/fermentation-solutions/you-create-beer/safale-wb-06/ 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 a [[Saccharomyces#Diastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'']] <ref>[https://fermentis.com/en/fermentation-solutions/you-create-beer/safale-wb-06/ Fermentis SafeAle™ WB-06 webpage. Retrieved 02/10/2018.]</ref>
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===[[Jasper Yeast LLC]]===
{| class="wikitable sortable"
|-
! Name !! Source !! Attenuation !! Flocculation !! Temp°F !! Notes
|-
| JY029 JY008 - Saint Nicholas, Belgian Wit Ale I || Hoegaarden Poperinge, Belgium || 70-77 78 || Low Med-High || 6368-76 78 || Spicy he yeast is very fruity and phenolicdoes well on a wide range of temperatures. At the lower temperatures maltiness comes more forward, with a nice estery finishand at the higher range yeast esters are more pronounced. <ref name="Jasper_Yeast">[https://jasperyeast.com/yeast/belgian "Belgian Yeast Strains". Jasper Yeast Website. Great for witbier]</ref>|-| JY011 - Belgian Ale II || Antwerp, Grand CruBelgium || 73-78 || Med-High || 62-style wit 74 || Rumored to originate from a famous brewery in Antwerp. Comparatively clean and specialty beersversatile. Produces less aromatics than other Belgian Stylesyeasts, mainly and is therefore more suited for malt-driven beers and Belgian Wit and Grand-Crustyle pale ales, but does well in Blondestill carries the Belgian aromatic flair. <ref name="Jasper_Yeast" />|-| JY027 - Belgian Ale V, Scourmont || Belgium || 76-81 || Med-High || 62-74 || Trappist yeast from one of the six Trappist breweries from Belgium. Strong fruity esters at elevated fermentation temperatures, Belgian Tripel but more subdued and Specialtyspicy at lower fermentation temperatures. <ref name="Jasper_Yeast" />
|-
| 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.
|-
| JY064 - Belgian Ale VII || Belgium || 70-80 || Low || 59-75 || Belgian Abbey yeast producing intense esters at higher temperatures, and strong spice notes at lower temperatures. <ref name="Jasper_Yeast" />
|-
| JY087 - Sacc Brux || Belgium || 70-80 || Very Low || 70-80 || Similar to Sacch Trois; forms a pellicle. Determined to be a [[Saccharomyces#Diastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'']] <ref name="Jasper_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.
|-
| 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.
|-
| JY164 - Belgian Ale XIV || East Flanders, Belgium || 75-80 || Low || 65-80 || Well suited for Golden Strong and other Belgian styles that do well with a spicy yeast strain. Can resist high ethanol concentrations. <ref name="Jasper_Yeast" />
|-
| JY206 - Belgian Ale XV || Ardennes, Belgium || 73-77 || High || 65-77 || Suitable for a wide variety of Belgian styles, depending on fermentation characteristics and grain bill. Tends to be spicy and fruity, with spiciness being on the forefront at lower fermentation temperatures, and estery at the higher range. <ref name="Jasper_Yeast" />
|-
| JY207 - 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. <ref name="Jasper_Yeast" />
|-
| JY240 - Belgian Ale VIII, Sixtus || Belgium || 78-86 || Low || 70-80 || Arguably the most used Trappist yeast outside of the original brewery. Well suited for the dryer Belgian styles such as Belgian Pale, Blonde, Tripel and Golden Strong. <ref name="Jasper_Yeast" />
|-
|}
===[[Lallemand Brewing]]===
{| class="wikitable sortable"
|-
! Name !! Source !! Attenuation !! Flocculation !! Temp°F !! Notes
|-
| SOURVISIAE® || Genetically engineered || Med-High || Med-High || 59-72 || GM Genetically engineered strain of ''S. cerevisiae'' that produces very high levels of lactic acid with a slightly fruity flavor and aroma and is free from off-flavors that can be produced by lactic acid bacteria such as THP. This yeast produces a very acidic beer, with final beer pHs in the range of 3.0 and lactic acid in the range of 8 – 15g/L. Vigorous fermentation can be completed within 5 days. It is not recommended to re-pitchby the manufacturer, although some brewers report success propogating propagating it into a larger biomass with a starter <ref>[https://www.lallemandbrewing.com/en/united-states/product-details/sourvisiae Sourvisiae. Lallemand Brewing website. Retrieved 11/22/2019.]</ref>. See also this [https://www.facebook.com/groups/MilkTheFunk/permalink/2907116972649831/ MTF thread] and this [https://www.masterbrewerspodcast.com/149 MBAA Podcast]. Evan Coppage reported getting 65-70% viability on subsequent re-pitches, with a slower start but comparable results to initial pitch (see [https://www.facebook.com/groups/MilkTheFunk/?post_id=3758907517470768&comment_id=375892069080278 this MTF thread]). See [http://suigenerisbrewing.com/index.php/2021/02/19/diving-deep-in-to-sourvisiae "Diving Deep In To Sourvisiae"] by Dr. Bryan Heit for fermentation and acidification dynamics, pitch rates, repitchability and other factors potentially of interest in the brewery.|-| [http://www.lallemandbrewing.com/product-details/belle-saison-beer-yeast/ Lallemand Belle Saison - DRY] || Lallemand || High || || 59-95 <ref name="Coppet" /> || Belle Saison is also a prodigious sulfur producer, so extended conditioning may be necessary. Verified to be a diastatic strain of ''Saccharomyces cerevisiae'', and killer neutral <ref name="Coppet">Marie, Coppet from Lallemand. Private correspondence with Martin Etchart; forwarded to Dan Pixley</ref><ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1561762887185253/?comment_id=1561820080512867&comment_tracking=%7B%22tn%22%3A%22R3%22%7D Conversation on MTF with Pierre Hugo Houle regarding Danstar Belle Saison yeast. 01/25/2017.]</ref><ref>[http://www.lallemandbrewing.com/product-details/belle-saison-beer-yeast/ Lallemand Brewing website. "BELLE SAISON BELGIAN SAISON-STYLE YEAST". Retrieved 11/20/2017.]</ref>. Belle Saison yeast is killer neutral, which means that killer wine strains will not kill it <ref name="Coppet" />. See [https://www.facebook.com/groups/MilkTheFunk/permalink/1561762887185253/ this MTF thread] for more information on this strain. This might be the same strain as WY3711 <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1890135267681345/?comment_id=1890160854345453&comment_tracking=%7B%22tn%22%3A%22R1%22%7D MTF Thread on Belle Saison. 11/20/2017.]</ref>. Formerly branded as "Danstar".|-| [http://www.lallemandbrewing.com/product-details/abbaye-belgian-ale-yeast/ 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". This strain has been reported to be a genetic hybrid between ''Saccharomyces cerevisiae'' and ''Saccharomyces kudriavzevii'' <ref>https://trace.ncbi.nlm.nih.gov/Traces/sra/?run=SRR10046972 Langdon QK, Peris D, Baker EP, Opulente DA, Nguyen HV, Bond U, Gonçalves P, Sampaio JP, Libkind D, Hittinger CT. Fermentation innovation through complex hybridization of wild and domesticated yeasts. Nat Ecol Evol. 2019 Nov;3(11):1576-1586. doi: 10.1038/s41559-019-0998-8. Epub 2019 Oct 21. PMID: 31636426; PMCID: PMC7295394.</ref><ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/4506794029348776/?comment_id=4507353275959518 Ben Sykes and Dan Pixley. Milk The Funk Facebook Post about T-58 vs Lallemand Abbaye being a hybrid yeast. 04/18/2021.]</ref>.
|-
|}
===[[Mainiacal Yeast]](CLOSED)===
{| class="wikitable sortable"
|-
| 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.
|-
|}
===[[Mogwai Labs]] (Australia)===
{| class="wikitable sortable"
|-
! Name !! Source !! Attenuation !! Flocculation !! Temp°C !! Notes
|-
| MOG-301 Reverence I || Trappist brewery in north Belgium || 70-76 || Low || 19-24 || Not diastatic.
|-
| MOG-301 Ardennes || || 70-76 || High || 19-24 || Not diastatic.
|-
|}
|-
! Name !! Source !! Attenuation !! Flocculation !! Temp°F !! Notes
|-
| BTN-46 Canadian Saison || A small craft brewery in Quebec || || || || Fall 2020 release; may not be available year round <ref>[https://www.propagatelab.com/product-page/btn-46-canadian-saison Propagate Lab website. "BTN-46 Canadian Saison." Retrieved 10/15/2020.]</ref>.
|-
| BTN-67 Anse || Bottle of organic, sparkling Gamay wine from Anse, France || || || || produces a fairly neutral profile with subtle white pepper, clove, and figs. It finishes very dry but has a fuller mouthfeel due to glycerol production <ref name="propagate_website" />.
|-
| MIP-211 Belgian Ale I || || Mid - High 70's || Med || 68-78 || Produces subtle banana esters <ref name="propagate_website">[https://www.propagatelab.com/yeastlibrary Propagate Lab website. "Yeast Library". Retrieved 11/18/2018.]</ref>.
|-
| 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%.
|-
|}
==Starters==
# [https://www.homebrewersassociation.org/how-to-brew/make-yeast-starter/ AHA guide to making yeast starters.]
# [https://www.homebrewersassociation.org/forum/index.php?topic=24447.30? Mark Van Ditta's "shaken, not stirred" starter method.]