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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]].

''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>.

| ''S. pastorianus'' || Lager-type Beer Fermentation. || Lager yeast; hybrid of ''S. eubayanus'' and ''S. cerevisiae'' <ref name="wikipedia_cereisiae">[https://en.wikipedia.org/wiki/Saccharomyces_pastorianus#Genomics Wikipedia. Saccharomyces pastorianus. Retrieved 02/12/2019.]</ref>

| ''S. eubayanus'' || Patagonia || Probable parent of lager yeast<ref name="libkind_2011">[https://www.ncbi.nlm.nih.gov/pubmed/21873232 Microbe domestication and the identification of the wild genetic stock of lager-brewing yeast. Libkind D1, Hittinger CT, Valério E, Gonçalves C, Dover J, Johnston M, Gonçalves P, Sampaio JP. 2011. DOI: 10.1073/pnas.1105430108]</ref><ref name="bing_2014">[https://www.ncbi.nlm.nih.gov/pubmed/24845661 Evidence for a Far East Asian origin of lager beer yeast. Bing J, Han PJ, Liu WQ, Wang QM, Bai FY. DOI: 10.1016/j.cub.2014.04.031.]</ref>

| ''S. kudriavzevii'' || Decayed leaves in Japan || Involved in hybrid strains used in commercial brewing and winemaking strains with ''S.uvarum'', ''S.cerevisiae'' and ''S.bayanus''.

* Kristoffer Krogerus's attempts to map the Gallon Gallone et al. codes to the commercial White Labs/Wyeast products and updated family tree dendrograms:

** [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).]

* [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"]

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 A newly discovered toxin that is related to create the K1 toxin, called "K1-like" or K1L, has been identified in ''S. cerevisiaeSaccharomyces paradoxus'' 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 The ability for this species to inhibit undesired yeast contaminants, preventing various off-flavors and other unwanted characteristics in the finished products. Ale and lager strains produce this toxin is caused by a virus that have been modified binds to release these toxins have reportedly retained the positive fermentation and flavor characteristics DNA of the original strains <ref name="Bajaj_2017" />yeast cells, and spread via horizontal gene transfer. Branco et alThe K1L toxin has a pH optimum mostly between 4. (2017 5 and 2019) discovered several strains of ''S5, with no inhibitory activity at pH 5.5. cerevisiae'' that excrete It is denatured at a biocin toxin that is active against several other genera temperature of yeast, including ''Brettanomyces bruxellensis''98°C. The toxin is composed A screening of peptides derived from the glycolytic enzyme glyceraldehyde-3this genetic change, called “K1-phosphate dehydrogenase like Killer Toxin” (GAPDHKKT)genes, which is a protein in other yeasts showed that serves many other species can also produce toxins similar to the K1L toxin but slightly different roles in different species of microbes and animals. This toxin is produced by some strains of effect, including ''S. cerevisiaeKazachstania africana'' 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 'Naumovozyma castellii'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 guilliermondiiNaumovozyma dairenensis'', ''Kluyveromyces marxianusTetrapisispora phaffii'', and ''Lactobacillus thermotoleransPichia membranifaciens'' (inhibited . Each of the identified species could kill at 250 μg/ml least one other type of yeast with its toxin, and was immune to its own toxin), while inhibition but susceptible to other K1-like toxins from other yeast species. Differences in the production of these K1-like toxins between 5 different strains of ''Torulaspora delbrueckiiP. membranifaciens'' and indicated that the toxins can be strain-specific, rather than species-specific. Using the genetic relatedness between the different KKT genes, the researchers concluded that this family of K1-like toxins originated outside of the ''B. bruxellensisSaccharomyces'' required very high amounts genus. This research uncovered a new family of K1-like antifungal killer toxins amoung many species of yeast in the toxin (500 μg/ml and 1000-2000 μg/ml) Saccharomycotina subphylum <ref>[https://linkjournals.springerplos.comorg/plosgenetics/article/?id=10.10071371%2Fs00253-016-7755-6 Antimicrobial properties and death-inducing mechanisms of saccharomycin, a biocide secreted by Saccharomyces cerevisiae2Fjournal.pgen. Patrícia Branco1009341 Fredericks LR, Diana FranciscoLee MD, Margarida MonteiroCrabtree AM, Maria Gabriela AlmeidaBoyer JM, Jorge CaldeiraKizer EA, Nils ArneborgTaggart NT, Catarina Prista, Helena Albergariaet al. 2017(2021) The Species-Specific Acquisition and Diversification of a K1-like Family of Killer Toxins in Budding Yeasts of the Saccharomycotina. DOIPLoS Genet 17(2): 10e1009341.1007/s00253-016-7755-6.]</ref><ref>[https://link.springerdoi.com/articleorg/10.10071371/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 Pristajournal. 2019pgen.1009341]</ref>.

* [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).]

=====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'' var. ''diastaticus''====

:Do a page search (CTRL+F) on this wiki page for the term "diastatic" or "diastaticus" to see all of the confirmed or suspected diasaticus diasatic strains listed in the [[Saccharomyces#Commercial_Farmhouse.2FBelgian_Strains_of_Saccharomyces|commercial culture charts]] below.

Diastatic strains of ''Saccharomyces cerevisiae'', historically designated as a variant of ''S. cerevisiae'' (''Saccharomyces cerevisiae'' var. ''diastaticus'' ), is a variant 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. However With the exception of a few strains, all such as the "Sacch Trois" strain, most diastatic ''diastaticuscerevisiae'' strains tested also produce phenols (POF+), which are considered off-flavors in one study produced phenols many beer styles other than Belgian ale styles and German Hefeweizen (there have been a couple of strains found that do not produce phenolsis no genetic link between POF+ and STA1 genes, such as and the Sacch Trois strainlink may just be coincidental due to human selection), with most being above flavor threshold. 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. doiDOI: 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]. When beer containing this yeast is packaged too early, it will continue to slowly ferment dextrins and cause over-carbonation. When pitching a proper cell count or pitching rate of a diastatic yeast strain into the wort, some strains will fully ferment as quickly or nearly as quickly as any other brewers yeast, while other strains may take as long as 16 days to fully ferment a simple 12.4°P (1.050 SG) wort. A highly dextrinous wort may take longer to fully ferment. The problem of slow fermentation in already packaged beer is usually only a concern when diastatic ''cerevisiae'' is introduced as a very small cell count, for example as an accidental contamination <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1982499288444942/?comment_id=1983013578393513&comment_tracking=%7B%22tn%22%3A%22R1%22%7D Caroline Whalen Taggart. Milk The Facebook post on how quickly diastatic ferments. 02/09/2018.]</ref>. The enzyme produced by these strains is heat stable and can continue to work on starches and dextrins even after the yeast is killed by heat pasteurization <ref>[https://www.mbaa.com/publications/tq/tqPastIssues/1983/Abstracts/tq83ab19.htm Factors That Control the Utilization Of Wort Carbohydrates by Yeast. G. G. Stewart, I. Russell, and A. M. Sills. MBAA Technical Quarterly, Vol. 20, No. 1, 1983.] </ref>. Almost all diastatic strains of ''S. cerevisiae'' are able to ulilize all of the sugars found in wort (e.g. glucose, fructose, sucrose, maltose, maltotriose), although one strain tested in a recent study could not efficiently ferment starch, maltose, (80%) or maltotriose (45%) <ref name="Meier-Dörnberg_2018" />. ''STA1+'' strains of ''S. cerevisiae'' can grow at 37°C and can also remain viable at refrigeration temperatures <ref>[http://www.ebc2017.com/inhalt/uploads/P095_Begrow.pdf Wade Begrow. "Recent notable microbiological contaminations of craft beer in the United States". Presentation poster at EBC 2017. Retrieved 11/19/2017.]</ref>. Some strains of diastatic ''cerevisiae'' are as flocculant as typical ale strains, while others are less flocculant <ref name="Meier-Dörnberg_2018" />. One strain of diastatic ''cerevisiae'', 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, although it is suspected to be). Other strains of diastatic ''cerevisiae'' may or may not be killer neutral (more data is needed; see [[Saccharomyces#Killer_Wine_Yeast|killer wine strains]] for more information on this topic).  Diastatic ''cerevisiae'' contamination in breweries has been a recent hot topic. These strains are effectively eliminated by standard cleaning and sanitation practices, although inadequate cleaning hygiene can lead to biofilm formation which makes them more resistant to cleaning regiments <ref name="Meier-Dörnberg" />. The source of some contaminations has also been suspected to potentially come from yeast suppliers, although there is no known percentage of infections which originate from yeast suppliers versus poor hygiene in the brewery. For example, a lawsuit by Left Hand Brewing Co. accused White Labs as being the source for the brewery's diastatic yeast contamination issues (see also [https://www.whitelabs.com/diastaticus this statement by White Labs]) <ref>[https://www.courthousenews.com/wp-content/uploads/2017/11/Left-Hand-v-White-Labs-COMPLAINT.pdf District Court, Boulder County, Colorado. Case Number 2017CV31132. Filed 11/14/2017.]</ref>. Detection of ''STA1+'' strains of ''S. cerevisiae'' as a contaminant can be difficult (see "Detection Methods" below). Contamination usually occurs as a secondary contaminant (meaning in the packaging system), and can come from contact with beer lines, by air circulation in the area of the packaging equipment, or by insufficient heat treatment of the packaging line. Since one viable cell that is able to divide can be enough to contaminate beer, contaminations can be sporadic with only a percentage of bottles being contaminated <ref name="Meier-Dörnberg_2018" />. Documented attenuation percentages above 75% for any strain of ''S. cerevisiae'' is also an indicator that the strain could be diastatic, however, some non-diastatic strains can also attenuate higher than 75%, so this indicator is not a reliable method to be sure that a given strain is ''STA1+'' <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2004689559559248/?comment_id=2004695002892037&reply_comment_id=2005133672848170&comment_tracking=%7B%22tn%22%3A%22R1%22%7D Adi Hastings. Milk The Funk Facebook Group post on non-diastatic strains with high attenuation. 02/27/2018.]</ref><ref name="mbaa_diastaticus" />. Often this contamination can only be detected by sensory testing weeks after packaging.  =====Detection Methods=====

This variant of ''S. cerevisiae'' yeast can produce extracellular glucoamylase (also called been detected using [httpshttp://enonlinelibrary.wikipediawiley.orgcom/wikidoi/10.1002/Alphaj.2050-glucosidase alpha-glucosidase0416.1981.tb04005.x/pdf LCSM agar plates], which is the same enzyme that although other species of wild ''[[Brettanomyces]]Saccharomyces'' produces to break down starches and dextrinsyeast can grow on this media <ref name="mbaa_diastaticus" />(~18 mins). This enzyme is released outside of the cell and can break down the α-1,4 linkages of starches and dextrins releasing glucose that PCR DNA analysis is then fermented by the yeast. The capability required to produce this enzyme is encoded by the give a positive identification of ''STA1+'' gene, which is a fusion strains of two other genes that are present separately in all ''S. cereivisaecerevisiae'' yeasts. Additionally, ''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 default level of CuSO<refsub>[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 diastaticus strains. 06/01/2019.]4</refsub>which is ~550 ppm (this can vary depending on manufacturer). Not all can inhibit some 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 diastatic ''STA1cerevisiae'' gene ; Wade Begrow of Saccharomyces cerevisiae (varFounders Brewing Co. diastaticus). Ana Cristina Adam, Lorena Latorre-Garcia, Julio Polaina. 2004.]recommends diluting the LCSM media with a basic malt media so that the CuSO<sub>4</refsub>. It has been reported by some microbiologists that most brewing strains that contain the ''STA1'' gene do produce the glucoamylase enzyme reaches around 200 ppm, or using LCSM plates modified with a gradient of CuSO<refsub>[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.]4</refsub><ref name="mbaa_diastaticus">[http://masterbrewerspodcast.com/068-diastaticus-part-1 Matthew Peetz of Inland Island and Tobias Fischborn of Lallemand. "Master Brewers Association PodcastBegrow_MBAA" 12/25/2017.]</ref>(~16 22 minsin). A study that surveyed 18 strains 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 ''diastaticus'' that contain the ''STA1'' gene found that only one was not able phenols via a gas chromatography or some other method can also be used to ferment dextrins <ref name="Meier-Dörnberg_2018" />. Richard Preiss has also reported indicate that WLP351 has the a yeast might be ''STA1+'' gene, but is not able to ferment dextrins since most strains produce phenols from these cinnamic acids <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/18880172112264842149139905114212/?comment_id=20130506953898012150763631618506&reply_comment_id=20133553120260062158975484130654&comment_tracking=%7B%22tn%22%3A%22R922R0%22%7D Richard PreissShawn Savuto and linked references. Milk The Funk Facebook group thread book post on diastaticus strains that do not ferment dextrins. March 2018.]</ref>. Krogerus et al. (2019) discovered that a region of genes just upstream of the ''STA1'' gene (promoter) called ''1162 bp'' 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 region is needed for the ''STA1'' gene to become effective. They also discovered that ''STA1POF+ correlation with diastatic '' 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 ''1162 bp'' promoter 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/10.1101/654681July 2018.]</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 also [https://www.facebook.com/groups/MilkTheFunk/permalink/26970881769860461903290776365794/ this MTF thread posted by Kristoffer Krogerus]on using cinnamic acids to identify phenolic off flavor strains).

When beer containing this yeast is packaged too earlyCheaper methods of doing PCR are recently becoming available, it will continue to slowly ferment dextrins and cause over-carbonation. When pitching a proper cell count or pitching rate of a ''diastaticus'' yeast strain into the wort, some strains will fully ferment could help breweries with smaller budgets sufficiently detect this as quickly or nearly as quickly as any other brewers yeast, while other strains may take as long as 16 days to fully ferment a simple 12.4°P contaminant (1see [[Laboratory_Techniques#PCR.050 SG2FqPCR|PCR Lab Techniques]]) wort. A highly dextrinous wort may take longer to fully ferment. The problem recent study used agar plates with 15 g/L^-1 of slow fermentation in already packaged beer is usually starch as the only a concern when ''diastaticus'' is introduced as a very small cell count, for example as an accidental contamination nutrient with 40 mg/L<refsup>[https://www.facebook.com/groups/MilkTheFunk/permalink/1982499288444942/?comment_id=1983013578393513&comment_tracking=%7B%22tn%22%3A%22R1%22%7D Caroline Whalen Taggart. Milk The Facebook post on how quickly diastaticus ferments. 02/09/2018.]-1</refsup>. The enzyme produced by these strains is heat stable and can continue bromophenol blue in anaerobic conditions to work on starches and dextrins even after detect the yeast is killed by heat pasteurization <ref>[https://wwwfermentation of starch (a pH drop from 5.mbaa2 to 4.com/publications/tq/tqPastIssues/1983/Abstracts/tq83ab196-3.htm Factors That Control 0 will change the color of the Utilization Of Wort Carbohydrates by Yeast. G. G. Stewart, I. Russell, and A. M. Sills. MBAA Technical Quarterly, Vol. 20, No. 1, 1983.] <agar plate to blue/ref>violet). Almost all For some of the slower growing strains of , 14 days were required to verify that they were ''S. cerevisiaeSTA1+'' varwhile other strains grew as quickly as two days and most strains grew after five days. ''diastaticus'' are able The yeast cells had to ulilize be thoroughly washed of all of the sugars found other carbohydrate material and starved in wort (eorder to avoid false positives.g. glucose, fructose, sucrose, maltose, maltotriose), although one strain tested in a recent study could not efficiently ferment Using dextrin agar plates instead of starch, maltose, (80%) or maltotriose (45%) also led to false positives <ref name="Meier-Dörnberg_2018" />. Note that diastatic ''S. cerevisiae'' var cells look the same under a microscope as regular ''S. cerevisiae'', so cell morphology is not an effective way to identify ''diastaticusSTA1+'' can grow at 37°C and can also remain viable at refrigeration temperatures strains <refname="Begrow_MBAA">[httphttps://www.ebc2017mbaa.com/inhalteducation/webinars/uploadsPages/P095_Begrowwebcast.pdf aspx?vid=diastaticus Wade Begrow. "Recent notable microbiological contaminations of craft beer in the United StatesS. cerevisiae var. diasttaicus". Presentation poster at EBC 2017MBAA webinar. Retrieved 11/19/2017July 2018.]</ref>(~8 minutes in). Some strains Other methods of ''diastaticus'' are as flocculant as typical ale strainsdetection include using a Durham tube/fermentation tube test to see if the beer produces CO² after fermentation, while others are less flocculant although this method does not identify the cause of the additional fermentation <ref name="Meier-Dörnberg_2018Begrow_MBAA" />(~18 mins in). One strain of More recently, Krogerus et al. (2019) developed more precise PCR primers to detect ''diastaticusSTA1''active, the Belle Saison strain from Lallemand''STA1'' non-active, is killer neutral, which means and non-''STA1'' based on their discovered role of an ''STA1'' promoter called ''1162 bp'' that killer wine strains will not kill it (it is not verified if Belle Saison is required for the same as WY3711, although it is suspected to be). Other strains of ''diastaticusSTA1'' may or may not gene to be killer neutral effective at producing the glucoamylase enzyme, however, PCR and qPCR have limited detection rates of 10^-4 and 10^-5 cells (more data is needed; see [http://beer.suregork.com/?p=4068 this Suregork Loves Beer blog post] and [Saccharomyces#Killer_Wine_Yeast|killer wine strains]https://www.facebook.com/groups/MilkTheFunk/permalink/2697088176986046/ this MTF thread posted by Kristoffer Krogerus] for more information on this topic).

Var. Detection of ''STA1+'' strains of ''diastaticusS. cerevisiae'' contamination in breweries has been as a recent hot topiccontaminant can be difficult. These 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 are effectively eliminated by standard cleaning and sanitation practices. Additionally, although inadequate cleaning hygiene PCR genotyping is sucseptable to user error or DNA detection from dead cells. Detection of the presence of starch degrading enzymes can lead to biofilm formation which makes them more resistant to cleaning regiments come from other contaminants such as ''Brettanomyces'' <ref name="Meier-DörnbergOmega_diastaticus_2020" />. The source of some contaminations has also Some agar media products and even starch/dextrin materials have been suspected to potentially come from yeast suppliers, although there is no known percentage contain small amounts of infections which originate from yeast suppliers versus poor hygiene in glucose or other simple sugar contaminants that can support the brewerygrowth of non-diastatic yeasts <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/3308119659216225/ Lance Shaner and Joshua Mayers. For example, a lawsuit by Left Hand Brewing CoMilk The Funk Facebook thread on Omega Yeast's STA1+ detection methods. 03/04/2020.]</ref>. accused White [[Omega Yeast Labs as being ]] reported that a slight alteration to the classic LCYM media recipe had significantly more reliable detection than classic LCYM and the source proprietary Weber diastatic agar for the breweryall ''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|''diastaticusSaccharomyces'' contamination issues (see also agar plates]] for the recipe and [https://www.whitelabsfacebook.com/diastaticus groups/MilkTheFunk/permalink/2874530432575152/ this statement MTF thread] by White 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 peer reviewed study on recommended detection methods)]) <ref>[https://www.courthousenewstandfonline.com/wp-contentdoi/uploadsfull/201710.1080/11/Left-Hand-v-White-Labs-COMPLAINT03610470.pdf District Court, Boulder County, Colorado2020. 1796175 Case Number 2017CV31132Laura T. Burns, Christine D. Filed 11/14/2017Sislak, Nathan L.]</ref>Gibbon, Nicole R. Detection of ''SSaylor, Marete R. cerevisiae'' varSeymour, Lance M. ''diastaticus'' as a contaminant can be difficultShaner & Patrick A. Contamination usually occurs as a secondary contaminant Gibney (meaning in the packaging system2020), Improved Functional Assays and can come from contact with beer lines, by air circulation in the area Risk Assessment for STA1+ Strains of the packaging equipmentSaccharomyces cerevisiae, or by insufficient heat treatment Journal of the packaging line. Since a very small number American Society of cells is enough to contaminate beerBrewing Chemists, contaminations can be sporadic with only a percentage of bottles being contaminated DOI: 10.1080/03610470.2020.1796175 .]</ref name="Meier-Dörnberg_2018" />. Documented attenuation percentages above 75% for any strain A summary of ''S. cerevisiae'' is also an indicator that the strain could be ''diastaticus'', however, some non-diastaticus strains can also attenuate higher than 75%, so this indicator Omega Yeast Lab detection methodology findings by Lance Shaner is not a reliable method to be sure that a given strain is ''diastaticus'' <ref>available [https://www.facebook.com/groups/MilkTheFunk/permalink/20046895595592483308119659216225/?comment_id=2004695002892037&reply_comment_id=2005133672848170&comment_tracking=%7B%22tn%22%3A%22R1%22%7D Adi Hastingshere on MTF]. Escarpment Labs built upon the work by Burns et al. Milk The Funk Facebook Group post on and developed a modified version of the Omega LCYM, and they reported it to have less false positives for non-diastaticus diastatic strains and it has reportedly been used for growing beer strains with high attenuation. 02/27/2018of ''Brettanomyces'' and ''Pichia''.See the [[Laboratory_Techniques#Saccharomyces|Escarpment SCCM media]]</ref><ref name="mbaa_diastaticus" />. Often this contamination can only be detected by sensory testing weeks after packaging.

This yeast can been detected using [http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1981.tb04005.x/pdf LCSM agar plates]In 2022, although other species of wild ''Saccharomyces'' yeast can grow on this media <ref name="mbaa_diastaticus" />(~18 mins) Ida Uotila and PCR DNA analysis is required to give Kristoffer Krogerus developed a positive identification of ''diastaticus''. Additionallysimple detection technique that only requires basic lab equipment (pipettes, centrifuge, the default level of CuSO₄ which is ~550 ppm (this can vary depending on manufacturerand heat block) can inhibit some strains of ''diastaticus''; Wade Begrow of Founders Brewing Co. recommends diluting the LCSM media with a basic malt media so that the CuSO₄ reaches around 200 ppm, gives results from beer or using LCSM plates modified yeast samples in 75 minutes, and with a gradient of CuSO₄ <ref name="Begrow_MBAA" /> (~22 mins in)accuracy as good as traditional PCR-based methods. Adding p-coumaric acid or other cinnamic acids to the LCSM agar media which can then The test for POF+ yeast and then confirmed for the presence of phenols via a gas chromatography or some other method result can also be used to indicate that visualized on a yeast might be ''diastaticus'' since there is a high occurrence of ''diastaticus'' to produce phenols from these cinnamic acids <ref>lateral flow strip. For more information, see [https://www.facebookbiorxiv.comorg/groupscontent/MilkTheFunk10.1101/permalink/2149139905114212/?comment_id=2150763631618506&reply_comment_id=2158975484130654&comment_tracking=%7B%22tn%22%3A%22R0%22%7D Shawn Savuto and linked references2022. Milk The Funk Facebook book post on POF+ correlation with ''diastaticus''11. July 201823.517627v1 their published paper]</ref> (see also [https://www.facebook.com/groups/MilkTheFunk/permalinkposts/1903290776365794/ this 6360775983950562 associated MTF thread] on using cinnamic acids to identify phenolic off flavor strains). [[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 diastaticus agar for all STA1 positive 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.

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^-1 of starch as the only nutrient with 40 mg/L^-1 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 ''diastaticus'' 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 diastaticus. 06/26/2018.]</ref>. Note that ''diastaticus'' cells look the same under a microscope as regular ''S. cerevisiae'', so cell morphology is not an effective way to identify ''diastaticus'' 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 CO² after fermentation, although this method does not identify the cause of the additional fermentation <ref nameCommercial Strains===="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^-4 and 10^-5 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]).

WY3711 saison yeast has been determined to be ''S. cerevisiae'' var. ''diastaticusSTA1+'' <ref name="preiss_diastaticus" />. Since yeast cannot be patented, many yeast labs are thought to offer this strain to customers. In the [[Saccharomyces#Commercial_Farmhouse.2FBelgian_Strains_of_Saccharomyces|commercial culture]] lists below where we believe a lab is selling this strain or another strain of ''diastaticus'' diastatic yeast, we note that it is determined or suspected to be ''diastaticusSTA1+''.

[https://www.whitelabs.com/yeast-bank/wlp885-zurich-lager-yeast WLP885] are potentially ''diastaticus'' diastatic (thanks to [https://gist.github.com/thcipriani/c303e39d6e8044307fa292cac6de6bd6 "thcipriani's" python script]), however, they do not designate if these strains actually ferment dextrins. Some hints as to which other White Labs products might also be ''diastaticus'' diastatic have been deduced from the [[Saccharomyces#History_of_Domestication|Gallone et al. study]] which 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 they correspond to. Some of the codes have been speculated on which White Labs strains they might refer to (see [[Saccharomyces#History_of_Domestication|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 [https://www.facebook.com/groups/MilkTheFunk/permalink/1400297539998456/?comment_id=1908170505877821&comment_tracking=%7B%22tn%22%3A%22R0%22%7D table], which has had reports of high attenuation and has been independently confirmed to be ''diastaticusSTA1+'' by Kristoffer Krogerus (it is also only one of two known examples of a ''diastaticus'' diastatic strain that are not also POF+; the other ''diastaticus'' diastatic strain that is POF- is WLP644) <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2095461573815379/?comment_id=2096044890423714&reply_comment_id=2105481916146678&comment_tracking=%7B%22tn%22%3A%22R%22%7D Kristoffer Krogerus. Milk The Funk Facebook thread on WLP026. 05/25/2018.]</ref><ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1400297539998456/?comment_id=1909596632401875&reply_comment_id=1910328215662050&comment_tracking=%7B%22tn%22%3A%22R9%22%7D MTF thread on ''STA1'' gene and White Labs strains that might have it or not. Milk The Funk Facebook group. 12/07/2017.]</ref>. There has been a report by Richard Preiss of [[Escarpment Laboratories]] that WLP570 (confirmed by White Labs) and [https://www.whitelabs.com/yeast-bank/wlp585-belgian-saison-iii-ale-yeast WLP585] both have the ''STA1'' gene, but it takes weeks before they hyper-attenuate <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1888017211226484/?comment_id=1911782002183338&reply_comment_id=1982274298467441&comment_tracking=%7B%22tn%22%3A%22R9%22%7D Richard Preiss. Milk The Funk Facebook group post on WLP570 and WLP585 being diastaticusdiastatic. 02/08/2018.]</ref>. Other yeast labs such as [http://www.lallemand.com/ Lallemand], [https://inlandislandyeast.com/yeast-library/inis-491-saison-french/ Inland Island], [https://www.escarpmentlabs.com/strains Escarpment Labs], and [https://www.theyeastbay.com The Yeast Bay] also list which strains they offer are ''diastaticus''diastatic.

* [http://suigenerisbrewing.com/index.php/2017/11/22/contamination-detection-1/ Sui Generis Brewing blog articles on using practical methods of PCR to identify diastaticus diastatic and other contamination for small breweries.]* [https://www.facebook.com/groups/MilkTheFunk/permalink/1888017211226484/ This MTF thread] on White labs lawsuit, identification via PCRand different agar media, and general contamination problemshandling.

* [https://www.reddit.com/r/TheBrewery/comments/5cx15c/qc_folks_any_experience_testing_for_s_diastaticus/ Reddit thread on detecting diastaticusdiastatic ''cerevisiae''.]* [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].

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 Blendand [[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>.

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>

Separated into two main lineages, "Saaz" and "Frohberg". The two lineages are believed to have descended from different hybridisation events between ''S. eubayanus'' and ''S. cerevisiae''. Emil Christian Hansen was the first in the world to isolate a single pure strain of ''S. pastorianus'' while he was working at the Carlsberg brewery, leading to its first the synonymous classification name, ''S. carlbergensis''. The type that Hansen isolated was a Saaz type, and it's believed that Saaz types are also prevalent in Bohemian / Czech ''S. pastorianus'' strains while German types are typically Frohberg. ([https://onlinelibrary.wiley.com/doi/full/10.1002/yea.2960] , [https://genome.cshlp.org/content/18/10/1610.full] )

This is in addition to [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, even 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.]

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Evidence, while sparse, shows that increased fermentation temperature does not seem to make a great difference in can increase the amount concentration of phenols produced by ''S. cerevisiae'' yeast<ref>[https://onlinelibrary.wiley.com/doi/full/10.1002/jib.189 Enhancing the levels of 4‐vinylguaiacol and 4‐vinylphenol in pilot‐scale top‐fermented wheat beers by response surface methodology. Yunqian Cui, Aiping Wang, Zhuo Zhang, R. Alex. Speers. 2015. DOI: https://doi.org/10.1002/jib.189.]</ref>. In ''Brettanomyces'', fermentation temperature can make small differences between yeastsfor some strains, but the differences are probably not large enough to detect during sensory testing (see [[Brettanomyces#Phenol_Production|''Brettanomyces'' phenol production]]) <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2776560529038810/?comment_id=2776928959001967&reply_comment_id=2776957078999155&comment_tracking=%7B%22tn%22%3A%22R%22%7D Richard Preiss. Milk The Funk Facebook group post on phenols and fermentation temperature. 07/09/2019.]</ref>. Schwarz et al. (2012) https://www.sciencedirect.com/science/article/pii/S0308814612006498

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 a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] <ref name="preiss_diastaticus" />.

===[[Bootleg Biology]]/[[Spot Yeast]]===

| 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 a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] if this strain is the same as WY3711 <ref name="preiss_diastaticus" />. Commercial pitches only.

| Dry Belgian Ale || || 85+ || Med-Low || 22-26 || Obtained from an American producer of Belgian-style beers. This strain exhibits classic dry Belgian flavours, and displays an aggressive primary fermentation. We especially like this strain for Strong Golden, Tripel, and other Belgian-style beers. NOTE: This strain contains the STA1 gene, meaning it might be a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] (pending data on whether it actually ferments dextrins or not). Many industrial yeasts are diastatic, due to the desire for very high attenuation levels. However extra care must be taken to ensure these yeasts do not cross-contaminate non-diastatic yeasts. Contact us with any questions or concerns. Alcohol tolerance: >12% <ref name="escarpment_strains" />.

| Old World Saison Blend || || 85+ || Med || 18-25 ||A characterful blend of two classic Saison strains. Produces complex fruit and black pepper notes along with a reliable, fast and high degree of attenuation. We strongly encourage a free rise fermentation, starting at 22C and rising to ~27C for optimal results. NOTE: One of the strains in this blend contains the STA1 gene, meaning it might be a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] (pending data on whether it actually ferments dextrins or not). Many Saison yeasts are diastatic, due to the desire for very high attenuation levels. However extra care must be taken to ensure these yeasts do not cross-contaminate non-diastatic yeasts. Contact Escparment Labs with any questions or concerns. Alcohol tolerance: High <ref name="escarpment_strains" />.

| St. Lucifer Belgian Ale || || 75-85 || Med || 20-24.4 || A high-character Belgian ale strain, able to produce high gravity beers with strong fruity and medium phenolic character. Excellent for strong golden ales and Tripels, but versatile for all Belgian ale applications. NOTE: This strain contains the STA1 gene, meaning it might be a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] (pending data on whether it actually ferments dextrins or not). Many industrial yeasts are diastatic, due to the desire for very high attenuation levels. However extra care must be taken to ensure these yeasts do not cross-contaminate non-diastatic yeasts. Contact us with any questions or concerns. Alcohol tolerance: >12% <ref name="escarpment_strains" />.

| 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 a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] if this strain is the same as WY3711 <ref name="preiss_diastaticus" />.

| B64 Napoleon || || 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 <ref name="IOY"></ref>. Determined to be a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] <ref name="preiss_diastaticus" />.

| 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 a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] <ref name="preiss_diastaticus" />.

| INIS-317 English Ale VII || || 65-69 || Medium || 80+ || This strain produces a malty beer that is slightly fruity for lower gravity beers. Very high alcohol tolerance makes this a good yeast choice for beers above 10% ABV. INIS-317 English Ale VII has been identified using polymerase chain reaction (PCR) to contain the glucoamylase gene (STA1), which can be an indicator of a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']]. As such, INIS-317 has the ability to utilize some dextrins which are unfermentable to most species of S. cerevisiae, and thus achieve a very high level of attenuation. However, INIS-317 is not considered a contaminant and will not over attenuate finished beer when a high level of attenuation is expected <ref>[https://inlandislandyeast.com/yeast-library/inis-317-English-Ale-VII/ INIS-317 English Ale VII. Inland Island website. Retrieved 02/27/2018.]</ref>.

| 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 a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain 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 <ref>[https://inlandislandyeast.com/yeast-library/inis-491-Saison-French/ INIS-491 Saison: French. Inland Island website. Retrieved 12/07/2017.]</ref>.

===[[Jasper Yeast LLC]]===

| 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" />

===[[Mainiacal Yeast]](CLOSED)===

| M29 French Saison Ale (previously M27) <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1258838617477683/?comment_id=1259047857456759&comment_tracking=%7B%22tn%22%3A%22R0%22%7D Conversation with Paul Finney about M29/M27. 03/21/2016.]</ref> || || 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 <ref>[https://cdn.shopify.com/s/files/1/0195/8620/files/72539_V1_MJ_CS_Yeast_Bk_lores.pdf Mangrove Jack's Craft Serieis Dried Yeast spec sheet. Retrieved 03/21/2016.]</ref>. Confirmed to be a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] <ref>Robbert Roost private email correspondance with Mangrove Jack customer service; forwarded to Dan Pixley. 12/14/2017.</ref>.

| 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 a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] <ref name="preiss_diastaticus" />. 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 a diastatic strain of ''S. cerevisiae'' var. ''diastaticus'' <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1378499435511600/?comment_id=1824967080864831&reply_comment_id=1825262140835325&comment_tracking=%7B%22tn%22%3A%22R0%22%7D Lance Shaner. Milk The Funk Facebook group on OYL-500. 09/18/2017.]</ref>. '''Available to homebrewers'''.

| MIP-350 Biere-de-Garde 330 French Ale Yeast || || Low 70's || High || 63-74 ||Good for malty saison styles and 12%+ ABV <ref name="propagate_website" />.

| RBY41 French Saison || || 77-83 || Low || 65-75 ||Determined to be a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] <ref name="preiss_diastaticus" />. Might be the same strain as WY3711.

| RVA 262 Saison II || || 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 a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] <ref name="preiss_diastaticus" />. Might be the same strain as WY3711

| 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 <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1131011020260444/?comment_id=1131279230233623&offset=0&total_comments=9&comment_tracking=%7B%22tn%22%3A%22R%22%7D Conversation with Nick Implellitteri and Ed Coffey on MTF. 08/19/2015.]</ref>. Determined to be a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] <ref>[https://www.theyeastbay.com/brewers-yeast-products/wallonian-farmhouse Wallonian Farmhouse. The Yeast Bay website. Retrieved 03/20/2018.]</ref>.

| Saison Blend II || || 80-86 || Med || 68-80 || This saison blend is the Saccharomyces portion of our Farmhouse Sour Ale, available to you as a result of popular demand from the commercial brewing crowd. This combination of Saccharomyces strains embodies the balanced fusion of the two foremost saison flavor/aroma characters, fruitiness and earthiness. Each Saccharomyces strain in this blend produces flavor compounds that serve as the yin to the other's yang, and the result is an exceptionally complex yet balanced flavor and aroma profile. One strain will serve to create an ester profile of grapefruit and orange zest, while the other will produce a mild earthiness and spiciness. Close your eyes while drinking a beer fermented with this blend, and you'll feel like you're laying on freshly turned earth in an old citrus grove. Contains a strain that is determined to be a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] <ref>[https://www.theyeastbay.com/brewers-yeast-products/saison-blend-ii Saison Blend II. The Yeast Bay website. Retrieved 03/20/2018.]</ref>.

| Dry Belgian Ale || || 85-100 || Med-High || 68-74 || Dry Belgian Ale is single strain of Saccharomyces cerevisiae isolated from a unique golden strong ale. The profile is a complex and balanced mix of apple, pear and light citrus fruit with some mild spicy and peppery notes. The apparent attenuation of this strain ranges anywhere from 85-100%, depending upon the mash profile and the grist composition. For a yeast that's as dry as it is, it creates beers with a surprising amount of balance even without the use of specialty grains or adjuncts. While we haven't completed our own tests in house, this yeast is used at the brewery from which it was isolated to make big beers that are in the neighborhood of 12-16% ABV and sufficiently dry. Use Dry Belgian Ale as a primary fermenter in any big Belgian beer, or to unstick that pesky stuck fermentation. Determined to be a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] <ref>[https://www.theyeastbay.com/brewers-yeast-products/dry-belgian-ale Dry Belgian Ale. The Yeast Bay website. Retrieved 03/20/2018.]</ref>.

| Funktown Pale Ale || || 78-80 || Medium-Low || 68-74 || Funktown Pale Ale is a blend of our Vermont Ale strain and <span style="text-decoration: line-through;">a unique strain of Brettanomyces that is well suited for primary fermentation</span> 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. Contains a strain that is determined to be a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] <ref>[https://www.theyeastbay.com/wild-yeast-and-bacteria-products/funktown-pale-ale Funktown Pale Ale. The Yeast Bay website. Retrieved 03/20/2018.]</ref>.

| 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 <ref>[http://www.theyeastbay.com/brewers-yeast-products/flanders-specialty-ale FLANDERS SPECIALTY ALE. The Yeast Bay website. Retrieved 02/06/2017.]</ref>. |-| Pakruojis Lithuanian Farmhouse || Not advertised || 90-100 || Low || 75-96 || Pakruojis Lithuanian Farmhouse is a single strain of STA1+ Saccharomyces cerevisiae, isolated from a Lithuanian brewery. This yeast produces beer with a dry, crisp and silky mouthfeel, an ester profile of citrus, and a balanced earthiness with undertones of white peppercorn. This strain exhibits high diastatic activity <ref>[https://www.theyeastbay.com/ The Yeast Bay website. Retrieved 03/09/2020.]</ref>.|-

| WLP570 - Belgian Golden Ale || Duvel (Moortgart) via McEwans <ref name="mrmalty_sources"></ref> || 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 <ref>[http://beer.suregork.com/?p=3907 Kristoffer Krogerus. "Decoding some White Labs strains from the Gallone et al. 2016 paper". Suregork Loves Beer blog. 10/22/2017. Retrieved 10/23/2017.]</ref>. Determined to be a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] <ref>[https://www.whitelabs.com/yeast-bank/wlp570-belgian-golden-ale-yeast WLP570. White Labs website. Retrieved 02/28/2018.]</ref>.

| WLP585 Belgian Saison III || || 70-74 || Med ||68-75 || Produces beer with a high fruit ester characteristic, as well as some slight tartness. Finishes slightly malty, which balances out the esters. Low levels of clove phenolics. Great yeast choice for a summer Saison that is light and easy-drinking. Seasonal Availability: Jul - Aug. Reported by Richard Preiss of [[Escarpment Laboratories]] that WLP585 has the STA1 gene that codes for a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']], but reported that it takes weeks before it hyper-attenuates <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1888017211226484/?comment_id=1911782002183338&reply_comment_id=1982274298467441&comment_tracking=%7B%22tn%22%3A%22R9%22%7D Richard Preiss. Milk The Funk Facebook group post on WLP570 and WLP585 being diastaticusdiastatic. 02/08/2018.]</ref>

| 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 a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] <ref name="preiss_diastaticus" /><ref>[https://www.whitelabs.com/yeast-bank/wlp590-french-saison-ale-yeast White Labs website. "WLP590 French Saison Ale Yeast". Retrieved 02/28/2018.]</ref>.

| 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'' <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1100249870003226/ Archive of MTF discussions regarding Trois genetic analysis results.]</ref>. White Labs classifies this as a "wild Saccharomyces" <ref>[http://www.whitelabs.com/sites/default/files/644_Explanation.pdf White Labs 644 Explanation. 04/09/2015. Retrieved 5/2/2015.]</ref>. Trois cannot ferment lactose <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1162272423800970/?comment_id=1162339237127622&offset=0&total_comments=8&comment_tracking=%7B%22tn%22%3A%22R1%22%7D Lance Shaner's results of fermenting Trois with lactose on MTF. 10/12/2015.]</ref>. It does not produce significant amounts of acetic or lactic acid, even under aerobic conditions <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1215686268459585/?comment_id=1215815188446693&reply_comment_id=1215856578442554&comment_tracking=%7B%22tn%22%3A%22R6%22%7D Conversation with Lance Shaner of Omega Labs on MTF. 01/17/2016.]</ref>. Therefore if acid (lactic or acetic) is found in a Trois beer, contamination would be the cause. It also does not produce phenols (POF-), but does produce higher amounts of esters than most strains of ''S. cerevisiae'' <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1978347765526761/?comment_id=1978387685522769&reply_comment_id=1980170622011142&comment_tracking=%7B%22tn%22%3A%22R%22%7D Richard Preiss. Milk The Funk Facebook post on Trois flavor profile. 02/06/2018.]</ref> <s>Approx. 500 million cells per mL; homebrew vials are approx. 17.5 billion cells at 35 mL <ref name="reddit_brett">[https://www.reddit.com/r/Homebrewing/comments/47qbgb/wlp644_cell_count_and_shelf_life/ Homebrewing Reddit post. 02/26/2016.]</ref>.</s> 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 <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1670851126276428/?comment_id=1672129959481878&comment_tracking=%7B%22tn%22%3A%22R0%22%7D Paul Illa. Milk The Funk Facebook group. 05/01/2017.]</ref>. Determined to be a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] <ref>[https://www.whitelabs.com/yeast-bank/wlp644-saccharomyces-bruxellensis-trois White Labs website. "WLP644 Saccharomyces "Bruxellensis" Trois". Retrieved 02/28/2018.]</ref>.

Retrieved 12/03/2018.]</ref>|| 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. Determined to be a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] <ref name="wyeast_diastaticus" />.

| 3711 - French Saison || || 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. [https://www.facebook.com/groups/MilkTheFunk/permalink/1329095693785308/ See this MTF thread for fermentation tips.] Determined to be a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] <ref name="preiss_diastaticus">[https://www.facebook.com/groups/MilkTheFunk/permalink/1888017211226484/?comment_id=1888076864553852&reply_comment_id=1888366977858174&comment_tracking=%7B%22tn%22%3A%22R2%22%7D Richard Preiss. Milk The Funk thread on diastaticusdiastatic S. cerevisiae. 11/18/2017.]</ref><ref name="wyeast_diastaticus">[https://www.facebook.com/groups/MilkTheFunk/permalink/2095461573815379/ Email from Jeannette Kreft-Logsdon. Milk The Funk Facebook post about Wyeast's diastaticus diastatic strains. 05/16/2018.] </ref>. This strain has been rumored to originate from the Brasserie Thiriez brewery <ref>[http://www.mrmalty.com/yeast.htm Kristen England. "Yeast Strain Sources". Mr. Malty website. Retrieved 05/29/2018.]</ref>, however, Daniel Thiriez claims that his brewery's strain of yeast is not the same as WY3711 <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/2109576319070571/?comment_id=2109874085707461&reply_comment_id=2109881735706696&comment_tracking=%7B%22tn%22%3A%22R0%22%7D Dave Janssen. Milk The Funk facebook group thread on WY3711 origins. 05/28/2018.]</ref>.

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 <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1378499435511600/?comment_id=1824967080864831&reply_comment_id=1824982287529977&comment_tracking=%7B%22tn%22%3A%22R5%22%7D Lance Shaner. Milk The Funk Facebook group post on S. boulardii. 09/18/2017.]</ref>. Determined to be a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] <ref name="wyeast_diastaticus" />.

| 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. Determined to be a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] <ref name="wyeast_diastaticus" />. '''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. Determined to be a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] <ref name="wyeast_diastaticus" />. '''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. Determined to be a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] <ref name="wyeast_diastaticus" />. '''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. Determined to be a [[Saccharomyces#Saccharomyces_cerevisiae_var._diastaticusDiastatic_strains_of_Saccharomyces_cerevisiae|diastatic strain of ''Saccharomyces cerevisiae'' var. ''diastaticus'']] <ref name="wyeast_diastaticus" />. '''Available from April through June 2016'''.

Homebrew Methods# [https://suigenerisbrewing.com/index.php/2022/09/20/optimizing-yeast-starters/ "Optimizing Yeast Starters" by Dr. Bryan Heit.]