Saccharomyces is considered a yeast, although this term is historical and ill-defined. Saccharomyces is a genus of fungus including many species. The distinct species of Saccharomyces are revised frequently as more research is done. All species are unicellular and capable of fermentation. Saccharomyces cerevisiae is the most well-known species of yeast. It is used in the fermentation of beer, wine, and sake, and as a leavening agent in bread. It is commonly referred to as "ale yeast", "wine yeast" (see Killer Wine Yeast below), or "bread yeast". S. pastorianus, known as lager yeast, is a hybrid closely related to S. cerevisiae but is not a true species. S. cerevisiae is commonly studied as a model organism and was the first eukaryote to have its genome entirely sequenced. In rare cases, Saccharomyces can form a pellicle.
- 1 Species
- 2 In Fermentation
- 3 Commercial Saison/Belgian Strains of Saccharomyces
- 3.1 BAC Yeast
- 3.2 Bootleg Biology
- 3.3 Craft Cultures
- 3.4 East Coast Yeast
- 3.5 Escarpment Laboratories
- 3.6 GigaYeast
- 3.7 Imperial Organic Yeast
- 3.8 Inland Island Yeast Laboratories
- 3.9 Jasper Yeast LLC
- 3.10 Mainiacal Yeast
- 3.11 Mangrove Jack's Dry Yeasts
- 3.12 Omega Yeast Labs
- 3.13 Propagate Lab
- 3.14 RBY Laboratories
- 3.15 RVA Yeast Labs
- 3.16 Saccharolicious
- 3.17 Sleight Beer Lab
- 3.18 SouthYeast Labs
- 3.19 The Yeast Bay
- 3.20 White Labs
- 3.21 Wild Pitch Yeast
- 3.22 Wyeast
- 3.23 Other Labs
- 4 Starters
- 5 Storage
- 6 See Also
- 7 References
Saccharomyces cerevisiae is the type species of the genus Saccharomyces, although Saccharomyces paradoxus, S. cerevisiae's closest relative, is likely older and more globally ubiquitous than S. cerevisiae.  Many previously recognized species of Saccharomyces have been consolidated or reassigned to another genus, commonly Zygosaccharomyces. 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) .
|S. cerevisiae||Domestic: Beer, Wine, Bread. Wild: Ripe fruits.||Believed to have been originally isolated from the skin of grapes|
|S. pastorianus||Lager-type Beer Fermentation.||Lager yeast; hybrid of S. eubayanus and S. cerevisiae |
|S. paradoxus||Deciduous trees (oak, maple, birch)||Closest known species to the baker's yeast|
|S. eubayanus||Patagonia||Probable parent of lager yeast |
|S. mikatae||Decayed leaves in Japan|
|S. kudriavzevii||Decayed leaves in Japan|
|S. bayanus||Wine||Hybrid of S. uvarum, S. eubayanus, and S. cerevisiae. Once proposed to be the parent of S. pastorianus, although this is no longer the consensus. Most wine making strains sold as S. baynus have been found to be S. cerevisiae instead .|
|S. florentinus||Drosophila and sulphurized grape must|
|S. arboricola||Cold tolerant||Produces high levels of ethyl esters |
|S. uvarum||Found in nature and fermented drinks, especially cold fermentated drinks .||Contains horizontal gene transfers from S. cerevisiae and S. kudriavzevii due to human-controlled beverage fermentation .|
Although it has been long understood that S. cerevisiae occurs naturally on bark and fruit, recent studies suggest that some Saccharomyces species are more abundant in leaf matter on the ground. See the "Where (Do) the Wild Yeast Roam" video by Bryan from Sui Generis blog and these studies/discussions:
- A systematic forest survey showing an association of Saccharomyces paradoxus with oak leaf litter.
- The interaction of Saccharomyces paradoxus with its natural competitors on oak bark.
- The natural ecology of Saccharomyces yeasts.
- Associated MTF thread.
History of Domestication
- Domestication and Divergence of Saccharomyces cerevisiae Beer Yeasts, by Gallone et al (2016); the first look at the domesticated S. ceresiae family tree and the grouping of two major genetic groups for domesticated ale yeasts: Beer 1 and Beer 2.
- Kristoffer Krogerus's attempts to map the Gallone et al. codes to the commercial White Labs/Wyeast products and updated family tree dendrograms:
- Kristoffer Krogerus's attempt to decode the strains in the above mentioned study ("Domestication and Divergence of Saccharomyces cerevisiae Beer Yeasts") and a redraw of the dendrogram family tree of ale yeasts as well as a spreadsheet that makes a best guess to map the strains in the study to actual White Labs strains.
- First update to the family tree of all of the yeast strains in the previously mentioned studies with commercial product names, by Kristoffer Krogerus.
- Second update to the family tree which includes kveik sequencing from Tyrawa et al (2018), as well as discussing strains that might be the same from different yeast labs.
- See also comments by Krisoffer on this MTF thread.
- Subsequent whole genome sequencing studies that grow the family tree of S. cerevisiae:
- Distinct Domestication Trajectories in Top-Fermenting Beer Yeasts and Wine Yeasts, by Gonçalves et al (2016).
- The origin and adaptive evolution of domesticated populations of yeast from Far East Asia, by Duan et al (2018); a study showing evidence for initial domestication of yeast in the Far East Asia.
- Genome evolution across 1,011 Saccharomyces cerevisiae isolates, by Peter et al (2018), which indated that domestication of yeast might have begun in Asia. See also this article and the associated MTF thread.
- 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 from Asia or were developed in Europe has not been clear and needs more research).
- Norwegian "kveik" yeast forms its own genetic group of yeast, indicating a subtree of the Beer 1 group.
- YouTube presentation by Kevin Verstrepen:
Killer Wine Yeast
Many wine yeast strains are known to be "killer" yeast strains that produce toxins that kill nearby yeast cells in order to give the killer yeast strains a competitive edge over sensitive strains (the term for these toxins has been changed to "zymocides" in science , but is also sometimes called "mycocins" or "zymocins" ). Unwanted killer strains of Saccharomyces have been suspected to cause stuck wine fermentations by killing off the sensitive wine strain that was pitched into the wine by the winemaker . In Saccharomyces, killer strains are genetically determined to secrete toxins (in the form of extracellular proteins or glycoproteins) that kill sensitive strains (there is no evidence that these toxins affect humans). These killer strains are immune to their own toxin. The mycocin toxins can act on sensitive strains in a number of ways: by blocking DNA synthesis and preventing cell division, inhibiting the synthesis of beta-glucans (β-1,6-glucan) that a part of their cell wall formation, and by causing ions to leak through the cell wall. In low dosages, which is typical in the natural environment, toxin triggers active cell death (apoptosis), while large dosages cause necrotic cell killing (necrosis). One study in wine found that the use of killer strains to outcompete sensitive strains resulted in off-flavors from yeast autolysis . Another study found that a lager strain that was genetically modified to secrete killer toxins was able to eliminate all cells of a sensitive ale strain within 24 hours of beer fermentation at a pitching rate of 99% sensitive ale strain to 1% killer lager strain, indicating that even a small amount of killer cells can be enough to kill a larger population of sensitive cells . Ratios of killer cells to sensitive cells that have shown to completely eliminate or nearly eliminate the sensitive population on lab media includes 1:1, 1;10, and 1:100. In a starter of a sensitive strain that had 10% cells of a killer strain introduced, the viability of the sensitive strain was greatly reduced . Neutral strains do not produce toxins, nor are they killed by them . Almost all domesticated ale and lager strains are sensitive to the toxins produced by killer strains .
In Saccharomyces cerevisiae, four toxins have been identified: K1, K2, K28, and Klus, the first three of which can only kill other strains/species of Saccharomyces. The Klus toxin has been found to kill all strains of S. cerevisiae (including those that produce the previous three toxins), as well as yeast from other genera, such as Hanseniaspora spp., Kluyveromyces lactis, Candida albicans, Candida dubliniensis, Candida kefir and Candida tropicalis. Rodriguez et al. (2011) reported that out of 1,114 strains of S. cerevisiae isolated from spontaneous wine fermentations, 38% of them were killer positive with most producing K2. Only 7% of produced the Klus toxin (no commercial wine yeast strains have been reported to produce the Klus toxin that we know of) . The K1 toxin is most active between a pH of 4.6 and 4.8, while K2 and Klus are active around a pH of 4.0 to 4.3 . The activity of the toxin is greatest during the log phase of growth, and decays during the stationary phase of fermentation . Generally, none of the toxins secreted by killer strains of Saccharomyces have been found to kill Brettanomyces . One study from India reported that a wild S. cerevisiae strain caught from flowers killed another wild caught strain of Brettanoyces anomulus, however, their methodology was not explicit and potentially not scientifically rigorous enough . For example, this study did not use DNA fingerprinting to identify the wild yeast strains used in the study and instead relied on morphology and media selection, and they did not identify the type of toxin produced by the killer strain of wild S. cerevisiae. They also reported that the B. anamulus strain did not ferment glucose, which is not typical for this species and indicates that it might have been misidentified.
Several strains of Saccharomyces eubayanus isolated from seeds from monkey puzzle trees in Patagonia, Argentina, were found to secrete a killer toxin that kills Brettanomyces and Pichia. One strain was found to produce a lot of the toxin, which is called "SeKT". S. cerervisiae strains, including strains that are sensitive to the above toxins, are not sensitive to this toxin. Mazzucco et al. (2019) found that SeKT toxin produced by this one strain of S. eubaynus in a special growth medium designed to maximize the SeKT toxin production (WUJ medium, which is "ultrafiltered" apple and pear juice) inhibited a strain of B. bruxellensis to around 50% growth after 48 hours in a wine growth medium. It also inhibited Pichia guilliermondii, Pichia manshurica, and Pichia membranifaciens by 50-70%. Note that the toxin was applied directly to the Brettanomyces and Pichia species, and not in a co-fermentation setting. Since S. cerevisiae strains are not effected by the SeKT toxin, it has been proposed as a way to limit Brettanomyces and Pichia in wine fermentations .
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 . For example, strains of the yeast species Candida pyralidae , Wickerhamomyces anomalus, Kluyveromyces wickeramii, Torulaspora delbrueckii and Pichia membranifaciens have been found to produce toxin that inhibits Brettanomyces . In addition, the toxin produced by Wickerhamomyces anomalus and Williopsis markii have been found to inhibit a wide range of spoilage and pathogenic fungi . Killer strains of S. cerevisiae and other yeast can occur naturally in the wild on fruit and can have a negative impact on other flora that are found in the same environment . Strains of Torulaspora delbrueckii have been shown to kill killer strains of S. cerevisae (wine strains), as well as to kill Pichia species . 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 . 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 .
Scientists have used genetic modification to create S. cerevisiae strains that produce various killer toxins that can assist in completing fermentation in the baking, wine, distillation, and beer making processes. These yeasts are able to inhibit undesired yeast contaminants, preventing various off-flavors and other unwanted characteristics in the finished products. Ale and lager strains that have been modified to release these toxins have reportedly retained the positive fermentation and flavor characteristics of the original strains . Branco et al. (2017 and 2019) discovered several strains of S. cerevisiae that excrete a biocin toxin that is active against several other genera of yeast, including Brettanomyces bruxellensis. The toxin is composed of peptides derived from the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH), which is a protein that serves many different roles in different species of microbes and animals. This toxin is produced by some strains of S. cerevisiae as they enter the stationary phase after primary fermentation. However, the amount of the toxin needed to inhibit B. bruxellensis was 10 times the amount that is produced naturally during fermentation. The researchers later genetically modified a strain of S. cerevisiae to over-produce the toxin, which they named "saccharomycin", at levels required to completely inhibit B. bruxellensis when co-pitched at a 1:1 ratio (10^5 cells/ml for both). This toxin was also reported to be highly active against Hanseniaspora guilliermondii, Kluyveromyces marxianus, Lactobacillus thermotolerans (inhibited at 250 μg/ml of toxin), while inhibition of Torulaspora delbrueckii and B. bruxellensis required very high amounts of the toxin (500 μg/ml and 1000-2000 μg/ml) .
- Bryan Heit's simple method for testing for killer sensitivity using nothing more than agar plates.
- List of killer strains as well as phenol production (4VG and 4VP) in various wine yeasts, compiled from a scientific study Hisamoto et al. (2010).
- For the implications of this on re-yeasting beer with wine yeast at packaging, see the Packaging page.
- For concerns about using bottle dregs from commercial sour beers that are bottled with wine or champagne yeast, see Commercial Sour Beer Dregs.
- Lallemand chart of wine yeasts and their Killer Factor.
- Another chart of wine yeast strain and killer factor (column labeled "Competitive Factor").
- Chris Lewis's write up on wine yeast character/Killer Factor on Lewy Brewing Blog.
- Shea Comfort notes on wine yeast on the BBB.
- "Brewing With Wine Yeasts" by Michael Tonsmeire". See also Dara McMains's MTF thread on beer fermentation with wine yeast and Brettanomyces.
Saccharomyces cerevisiae var. diastaticus
- Do a page search (CTRL+F) on this wiki page for the term "diastaticus" to see all of the confirmed or suspected diasaticus strains listed in the commercial culture charts below.
Saccharomyces cerevisiae var. diastaticus is a variant of S. cerevisiae that can ferment certain types of starches and dextrins, and has been identified as a contaminant in breweries and is responsible for a few large recalls. 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, all diastaticus strains tested in one study produced phenols (there have been a couple of strains found that do not produce phenols, such as the Sacch Trois strain), 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 . 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 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 .
This variant of S. cerevisiae can produce extracellular glucoamylase (also called alpha-glucosidase, which is the same enzyme that Brettanomyces produces to break down starches and dextrins). This enzyme is released outside of the cell and can break down the α-1,4 linkages of starches and dextrins releasing glucose that is then fermented by the yeast. The capability to produce this enzyme is encoded by the STA1 gene, which is a fusion of two other genes that are present separately in all S. cereivisae 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 ). Not all strains containing one of these genes produce the glucoamylase enzyme or are as effective as others at metabolizing dextrins . It has been reported by some microbiologists that most brewing strains that contain the STA1 gene do produce the glucoamylase enzyme (~16 mins). A study that surveyed 18 strains of diastaticus that contain the STA1 gene found that only one was not able to ferment dextrins . Richard Preiss has also reported that WLP351 has the STA1 gene, but is not able to ferment dextrins . 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 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 . For more details on the Krogerus et al. (2019) study, see this Suregork Loves Beer blog post and 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 diastaticus 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 diastaticus is introduced as a very small cell count, for example as an accidental contamination . 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 . Almost all strains of S. cerevisiae var. diastaticus 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%) . S. cerevisiae var diastaticus can grow at 37°C and can also remain viable at refrigeration temperatures . Some strains of diastaticus are as flocculant as typical ale strains, while others are less flocculant . One strain of diastaticus, the Belle Saison strain from Lallemand, is killer neutral, which means that killer wine strains will not kill it (it is not verified if Belle Saison is the same as WY3711, although it is suspected to be). Other strains of diastaticus may or may not be killer neutral (more data is needed; see killer wine strains for more information on this topic).
Var. diastaticus 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 . 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 diastaticus contamination issues (see also this statement by White Labs) . Detection of S. cerevisiae var. diastaticus as a contaminant can be difficult. Contamination usually occurs as a secondary contaminant (meaning in the packaging system), and can come from contact with beer lines, by air circulation in the area of the packaging equipment, or by insufficient heat treatment of the packaging line. Since a very small number of cells is enough to contaminate beer, contaminations can be sporadic with only a percentage of bottles being contaminated . Documented attenuation percentages above 75% for any strain of S. cerevisiae is also an indicator that the strain could be diastaticus, however, some non-diastaticus strains can also attenuate higher than 75%, so this indicator is not a reliable method to be sure that a given strain is diastaticus . Often this contamination can only be detected by sensory testing weeks after packaging.
This yeast can been detected using LCSM agar plates, although other species of wild Saccharomyces yeast can grow on this media (~18 mins) and PCR DNA analysis is required to give a positive identification of diastaticus. Additionally, the default level of CuSO4 which is ~550 ppm (this can vary depending on manufacturer) 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, or using LCSM plates modified with a gradient of CuSO4  (~22 mins in). Adding p-coumaric acid or other cinnamic acids to the LCSM agar media which can then test for POF+ yeast and then confirmed for the presence of phenols via a gas chromatography or some other method can also be used to indicate that a yeast might be diastaticus since there is a high occurrence of diastaticus to produce phenols from these cinnamic acids  (see also this 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 Saccharomyces agar plates for the recipe and 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 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 . This starch media has been recommended by Richard Preiss from Escarpment Laboratories and Justin Amaral from Mainiacal Yeast . 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  (~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  (~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 this Suregork Loves Beer blog post and this MTF thread posted by Kristoffer Krogerus).
WY3711 saison yeast has been determined to be S. cerevisiae var. diastaticus . Since yeast cannot be patented, many yeast labs are thought to offer this strain to customers. In the commercial culture lists below where we believe a lab is selling this strain or another strain of diastaticus yeast, we note that it is determined or suspected to be diastaticus.
White Labs now reports that the strains WLP045, WLP073, WLP099, WLP545, WLP566, WLP570, WLP590, WLP644, WLP740, and WLP885 are potentially diastaticus (thanks to "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 have been deduced from the 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 History of Domestication above). The strains from the Gallone paper that appear to contain STA1 are Beer002, Wine019, Beer092 and Beer059. The Beer059 code might correspond to WLP026 according to this speculative table, which has had reports of high attenuation and has been independently confirmed to be diastaticus by Kristoffer Krogerus (it is also only one of two known examples of a diastaticus strain that are not also POF+; the other diastaticus strain that is POF- is WLP644) . There has been a report by Richard Preiss of Escarpment Laboratories that WLP570 (confirmed by White Labs) and WLP585 both have the STA1 gene, but it takes weeks before they hyper-attenuate . Other yeast labs such as Lallemand, Inland Island, Escarpment Labs, and The Yeast Bay also list which strains they offer are diastaticus.
- Kristoffer Krogerus explains his discovery of the STA1 promoter gene that explains why some STA1 positive strains do not effectively ferment starches or dextrins, as well as the occurence of this promoter gene within the Beer 2 yeast group and lack of it in wild yeast, new PCR primers for detecting active vs non-active STA1 strains.
- Escarpment Labs PCR protocol for testing for STA1, including details on the limitations of PCR testing and Part 2, identifying using starch agar plating and LCSM plating.
- Sui Generis Brewing blog articles on using practical methods of PCR to identify diastaticus and other contamination for small breweries.
- This MTF thread on White labs lawsuit, identification via PCR, and general contamination problems.
- ASBC "Rapid Methods for Detecting Saccharomyces diastaticus, a Beer Spoilage Yeast, Using the Polymerase Chain Reaction."
- Reddit thread on detecting diastaticus.
- MBAA Podcast on diastaticus Part 1 and Part 2.
- MBAA webinar by Wade Begrow (free for MBAA members, $50 for non-members).
Saccharomyces cerevisiae var boulardii
Although originally designed as a separate species (S. boulardii), it is actually a variety of S. cerevisiae and shares more than 99% of the genetic makeup of S cerevisiae . This strain is sold by East Coast Yeast in their ECY03 Farmhouse Blend.
Some species of this genus cannot ferment maltose or maltotriose, which make up the majority of sugar in brewer's wort. For example, Bellut et al. (2018) found that one strain that was isolated from kombucha could not ferment these complex sugars. This is due to the lack of a maltose transporter and the enzyme maltase. It also could not ferment melibiose, but could ferment glucose, fructose, sucrose, raffinose, and cellobiose. As such, they have been proposed as being potentially useful in non-alcoholic beer fermentation. Additionally, these species were able to grow in 7◦ Plato wort with a range of IBU (50 IBU was the maximum IBU tested), indicating that IBU's don't impact the growth of these species. They also lacked the ability to produce phenols. It was described as moderately flocculant, with the flocculation depending on the FLO gene and the presence of calcium in the wort (the same as Saccharomyces). They produced much less higher alcohols (n-propanol, isobutanol, and isoamyl alcohol) than the WLP001 control yeast, and fewer esters, and about the same amount of acetaldehyde and diacetyl than WLP001 .
This species may not be genetically distinct from S. cerevisiae .
Probable parent of lager yeast (S. pastorianus) through hybridisation with S. cerevisiae . Isolated and described in 2011 growing within Nothofagus trees in Patagonia, Argentina. Samples have also been found in Tibet, China and New Zealand.
- Example beer made with Eubayanus: BREWING WITH SACCHAROMYCES EUBAYANUS
Known available strains:
Commonly known as lager yeast to brewers, this yeast is a hybrid of S. eubayanus and S. cerevisiae . 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 .
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) 
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 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. ( ,  )
With recent whole genome sequencing data, it has been discovered that some strains of commercial yeast have been misidentified as either lager yeast or ale yeast. Ben Sykes reported that publicly available genetic data for an upcoming study indicates that WLP800, the Czech lager yeast from White Labs, is potentially S. cerevisiae (ale yeast). WLP029 German Ale/ Kölsch Yeast is potentially lager yeast.
WLP051 California V Ale yeast is also S. pastorianus. Recent gene sequencing / PCR work has led to it being re-classified as a S. pastorianus yeast, though it has been used successfully for American-style Ale production.
Fermentation Under Low pH Conditions
Saccharomyces species and individual strains have a wide range of tolerance to low pH and lactic/acetic acid concentrations, which have been identified as stressors for yeast fermentation. For ideal fermentation conditions for S. cerevisiae, lactic acid should not exceed 0.8%, acetic acid should not exceed 0.5%, and wort should not fall below 4.0 pH. Since pH is on a log-based scale, even small differences in pH (especially below 3.5) can make a large impact on whether or not a given yeast strain is able to ferment. This obviously presents a challenge to brewers when Wort Souring or naturally carbonating with yeast for sour beers .
Yeast that fails to bottle condition sour beer may not be due to death of the cells. Rogers et al.  published a study that found that yeast used to bottle condition a sour beer at Upland Brewing Co. was still ~80% viable after two weeks, but the surviving cells were small and unbudded, indicating that they ceased growing and entered the stationary phase. This effect has been referred to as "terminal acid shock" .
As stated previously, lactic acid and low pH are identified as stressors for yeast, and can affect their ability to carbonate sour beer. Some strains tested display an ability to grow in higher lactic acid concentrations, while others do not, but this does not indicate that they are able to bottle condition sour beer. For example, WLP001 and WY1056 do not grow well in YPD dosed with lactic acid, whereas Lallemand CBC-1 ("Cask & Bottle Conditioned Beer Yeast") can still grow at a pH of 3. WY2007 and WLP300 grow well in moderate levels of lactic acid, but not once the pH gets down to 3. WLP715 Champagne Yeast grows fine in a pH of 3 (although lag time is effected). However, despite being able to grow in YPD with lactic acid dosages, CBC-1 and WLP715 both failed to carbonate an 8% ABV sour beer that had a comparable pH to the pH of the YPD plus lactic acid mediums. It is suggested that this might be due to the combination of stress from high alcohol, acetic acid, low nutrients, low oxygen, and tannins from fruit. Re-hydrating dried yeast may also lead to difficulties carbonating acidic and high ABV (8%+) sour beer due to the stress of desiccation and re-hydration on the yeast .
Rogers et al. found an easy solution to carbonating low pH, high ABV beers by first acclimating the yeast to the sour beer. Growing the yeast in YPD plus lactic acid plus ethanol was not enough to acclimate the yeast and reliably carbonate a highly acidic, alcoholic (8% ABV) beer. However, by growing the yeast first in a blend of YPD that was diluted with the sour beer itself in a 1:1 ratio, they found that both CBC-1 and WLP715 were then able to carbonate the sour beer (WLP001, WY1056, WY2007, and WLP300 were not given this treatment). This was explained as exploiting the microbes' resilience and ability to adapt to many environmental conditions by "pre-adapting" the yeast to the harsh conditions of the sour beer . It has been speculated that brewers without access to YPD might be able to achieve similar results by growing the conditioning yeast in sour beer diluted with DME wort and yeast nutrients (Fermaid K and DAP, for example) .
A second study showed that a strain of S. cerevisiae was able to adapt and grow in a lab setting to increasing concentrations of lactic acid. After multiple generations and by slowly increasing the amount of lactic acid per generation, the researchers got the pH of the growth media (either raffinose or glucose plus lactic acid) all the way down to pH 2.8. At this low pH, the yeast began to use lactic acid as a food source. This might explain some anecdotal experiences by brewers who have seen the pH of kettle sour beers rise (more evidence is needed to confirm this hypothesis). The researchers found that the gene called ACE2 is likely to be associated with the ability to adapt to low pH conditions. It is also a gene that controls the expression level of other genes, and is also responsible for forming "snowflake-like" structures (multicellular clumps of genetically identical cells that stick together after budding ). The yeast strain began to form these "snowflake-like" clumps after being adapted to the low pH environment. Further work should be done to determine which strains of S. cerevisiae might be more easily adapted to low pH environments, or if possibly all strains of S. cerevisiae could be adapted to low pH environments over time .
- Lactic Acid
- Acid Shock Starters
- Wort Souring
- The Sour Hour interview with Dr. Matt Bochman
- "Biochemist finds solution to 'acid shock' in craft brewers' sour beer production", article on Phys.org.
- "Quick Sour, then what? Acid Tolerance of Brewer’s Yeast" by Michael Tonsmeire
Phenolic Off Flavor Strains
Some strains of S. cerevisiae can convert the ferulic acid, which is found in malted barley and in wheat (malted wheat more so than raw wheat), into the phenol 4-vinyl guaiacol (4VG). 4VG is less toxic to microorganisms than the ferulic acid and other hydroxycinnamic acids. It gives a clove-like flavor to the beer. While most beer styles consider this an off-flavor, it is an important flavor component for certain styles of beer such as German Hefeweizen, saison, and some Belgian styles. Strains that convert ferulic acid into 4VG during fermentation are known as "phenolic off flavor positive" or "POF+" and are characteristic of wild Saccharomyces, bread yeast, and a small number of brewers yeast. Most strains of brewers yeast, however, were selected for not having this capability, and are known as "phenolic off flavor negative" or "POF-". POF+ strains require two enzymes: phenylacrylic acid decarboxylase (Pad1) and a ferulic acid decarboxylase (Fdc1). The Pad1 enzyme creates a precursor required for the Fdc1 enzyme to work, which then converts the ferulic acid into 4VG. These enzymes are dictated by the presence of the PAD1 and FDC1 genes respectively . Yeast produced phenolic/clove aromas tend to dominate over hop aromas in dry hopped beer .
Evidence, while sparse, shows that fermentation temperature does not seem to make a great difference in the amount of phenols produced by S. cerevisiae yeast. In Brettanomyces, fermentation temperature can make small differences between yeasts, but the differences are probably not large enough to detect during sensory testing (see Brettanomyces phenol production) . Schwarz et al. (2012) https://www.sciencedirect.com/science/article/pii/S0308814612006498
While most beer strains of S. cerevisiae are POF-, a survey of over 200 strains of S. cerevisiae showed that 81-95% of wine yeasts are POF+. It was also shown that 85-97% of wild strains of S. cerevisiae are POF+. Other genera of yeasts that tend to be POF+ include Rhodotorula, Candida, Cryptococcus, Pichia, Hansenula, and Brettanomyces .
- Phenols produced by Brettanomyces.
- Kristoffer Krogerus's blog article on removing POF gene from Saccharomyces hybrids.
- MTF thread on detecting POF+ on agar.
Commercial Saison/Belgian Strains of Saccharomyces
In cooperation with Eric Bandauski .
|BY122||Achouffe||72-76%||High||64-84||One of many great beer yeast to produce classic Belgian ales. Phenolics develop with increased fermentation temperatures, mild fruitiness and complex spicy character. Similar to WLP550 or WY3522.|
|BY124||77-83%||Low||65-77|| French Saison yeast starter is a strain that enhances the use of spices and is extremely attenuative yet leaves an unexpected silky and rich mouthfeel in a very dry finished beer.
Produces Saison or farmhouse-style beers that are highly aromatic with clean citrus esters. Expect peppery and spicy notes with no earthiness and low phenols. This strain enhances the use of spices and is extremely attenuative but leaves an unexpected silky and rich mouthfeel in a very dry finished beer. Similar to WY3711. Determined to be Saccharomyces cerevisiae var. diastaticus .
|BY125||Saison du Pont||76-80%||Low||70-85|| Belgian Saison Classic farmhouse ale yeast. Very tart and dry on palate with mild fruit. Finishes crisp and mildly acidic. Benefits from elevated temperatures.
Classic farmhouse ale yeast. Spicy and complex aromatics including bubble gum. Very tart and dry on palate with mild fruit. Finishes crisp and mildly acidic. Benefits from elevated fermentation temperatures. Usually slow to attenuate. Similar to WLP565 or WY3724.
|BY126||Westmalle||75-80%||Medium||64-78||Trappist Big ABV strain is a robust top cropping beer yeast with phenolic character. Trappist Big ABV beer yeast has an alcohol tolerance to 12%. It's ideal for Bière de Garde, as it ferments dry with rich ester profile and a malty palate. Similar to WLP530 or WY3787.|
|BY128||Esen, Belgium (De Dolle)||72-76%||Medium||62-75|| This versatile witbier yeast strain can be used in a variety of Belgian style ales. This strain produces a complex flavor profile dominated by spicy phenolics with low to moderate ester production. It is a great strain choice when you want a delicate clove profile not to be overshadowed by esters. It will ferment fairly dry with a slightly tart finish that compliments the use of oats, malted and unmalted wheat. This strain is a true top cropping yeast requiring full fermenter headspace of 33%
A tart, slightly phenolic yeast capable of producing distinctive witbiers and grand cru-style ales alike. Alcohol tolerant. Similar to WY3942.
|BB22204 - S. arlingtonesis||Wild yeast starter jar in Arlington, VA||High||NA||60-70||This culture ferments extremely cleanly in the low 60’sF (Kölsch and Lager hybrids), and subtle fruity/citrus esters in the higher end of the Ale fermentation range (wheat-centric beers). May produce sulfur aromas during primary fermentation, but those will be eliminated within a couple weeks (allow longer aging if fermenting at lower temperatures). S. arlingtonesis is a higher attenuator than most ale strains, so adjustments made need to be made to grain bills or mash temperatures if a drier beer is not preferred.|
|BBX0104 – Saison Parfait: New World Saison Blend||A unique blend of previously unavailable commercially used Saison cultures.||90-100||Med-High||Normal to High Ale Temperatures||Saison Parfait is our New World Saison Blend, a new take on the modern saison yeast flavor and aroma profile. Saison Parfait pairs classic pepper & spice saison phenolics with prominent juicy fruit esters that evoke citrus and lemon peel, and a touch of banana for complexity. Even more unique, it finishes with a balanced, full-bodied and silky mouthfeel despite its high attenuation. Saison Parfait means the “Perfect Season”, and is our ode to the fall harvest season. A time for hard work and also celebration. The peasants of rural Flanders and Wallonia created the Saison, and what we now call Farmhouse beers, to drink for sustenance and merriment. Bruegel likely depicted the drinking of Saison beer in his classic paintings of rural country life, “The Harvesters” and “Peasant Wedding”.|
|CCYL113 - Belgian Saison Ale Yeast||This yeast strain contributes clove flavor and aroma to the finished product. Fruity aromas are also experienced. Commercial pitches only.|
|CCYL114 - Belgian Ale Yeast||To produce any great distinctive Belgian style beer, do ferment with the Belgian Ale Yeast. Flavors emanating from beer produced by this yeast are rich in both spice and phenols and are mildly fruity. Commercial pitches only.|
|CCYL115 - Trappist Ale Yeast||The Trappist Ale Yeast has a unique fruit and plum flavor and aromas. It performs well in high gravity brews. Commercial pitches only.|
|CCYL116 - Belgian Wit Ale Yeast||The original yeast used to produce Belgian Witbier and a variety of other Belgian style ales. Commercial pitches only.|
|CCYL120 - French Saison Ale Yeast||The French Saison Ale Yeast is a versatile strain that works great for Saison or Farmhouse and other Belgian style beers where aromatic (estery), peppery, spicy and citrusy flavors are desired. Might be Saccharomyces cerevisiae var. diastaticus if this strain is the same as WY3711 . Commercial pitches only.|
|CCYL121 Abbey Ale Yeast||Used to produce Trappist, Belgian, Belgian doubles and triples This yeast contributes a fruity characteristics. Excellent alcohol tolerance for high gravity beers. Commercial pitches only.|
|CCY126 French Ale Yeast||Clean strain that complements malt flavor. Low to moderate esters, when fermentation temperature is below 70°F. Moderate plus ester character over 70°F. Low diacetyl production. Good yeast strain for Biere de Garde, blond, amber, brown ales, and specialty beers. Commercial pitches only.|
|CCYL128 - Belgian Saison Ale Yeast Blend||The Belgian Saison Ale Yeast Blend has some phenolic and clove-like flavor and aroma characteristic and fruitier esters than CCYL113. Ferments faster than CCYL113. Commercial pitches only.|
|CCYL129 - Eagle River Ale Yeast™||Michigan indigenous. The Eagle River Ale Yeast is the second in a series of indigenous Michigan strains. It was isolated from the shore of Lake Superior near Eagle River Michigan. This yeast will produce excellent Belgian style ales. This yeast is rich in both spice and phenols exhibits predominantly fruity esters, similar to a Belgian ale strain. Commercial pitches only.|
|CCYL130 - Keweenaw Ale Yeast™||Michigan indigenous. The Keweenaw Ale Yeast is the third in a series of indigenous Michigan yeast strains. This yeast was isolated in Michigan's Keweenaw Peninsula. It has prominent spicy phenolics and some fruity esters, very reminiscent of a Saison yeast. Commercial pitches only.|
|CCYL131 Belgian Wit Ale 2.0||Less Belgian-like phenolics than CCYL116 and more spicy. Will leave a bit more sweetness, and flocculation is higher than CCYL116. Use to produce Belgian Wit, spiced Ales, wheat Ales, and specialty Beers. Commercial pitches only.|
|CCYL134 Rock Cut Ale Yeast™||Michigan indigenous yeast coming soon. Commercial pitches only.|
|CCYL138 Rock Cut Ale Yeast II™||Michigan indigenous yeast coming soon. Commercial pitches only.|
|ECY03 Farmhouse Blend||A saison blend (ECY08) with a wild isolate from a small producer of Saison. Can produce a funky and acidic farmhouse ale particularly when a secondary fermentable is added (i.e. priming sugar or fruit). The wild isolate, ECY03B, now identified as Saccharomyces boulardii - is a wild-type strain of Saccharomyces cerevisae. Commercial orders will also include a small pitch of ECY03B with the ECY03 primary pitch. Pitching the 03B during high krausen also produces the "wildness" quickly without aging long-term .|
|ECY-03B Farmhouse||Fantome||80||70-84||Previously misidentified as Brettanomyces . Fruity and funky profile with some acidity gradually increasing over time. Aeration has more of a muted effect. Identified as Saccharomyces boulardii .|
|ECY08 Saison Brasserie||Several Strains||80+||75-85||Several saison yeast strains for both fruity and spicy characteristics accompanied with dryness. See also tasting notes from MTF members.|
|ECY14 Saison Single||Single Strain||76-78||75-82||Smooth, full farmhouse character with mild esters reminiscent of apple pie spice|
|Ardennes Belgian Ale||72-80||Med-High||18.3-24.4||A very versatile and production-friendly Belgian ale yeast, producing balanced Belgian esters and spicy notes. One of the rare Belgian strains which flocculates relatively well, making repitching and/or cropping easier when compared to other Belgian yeasts. Alcohol tolerance: high .|
|Classic Witbier||72-78||Med-Low||19-24||Medium alcohol tolerance. A genera-defining Witbier strain, famous for balanced phenol and ester character with slight tartness that emphasizes wheat flavour |
|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 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% .|
|Fruity Witbier||70-75||Med-Low||17-24||A Witbier strain which produces lots of complex fruity esters while still prominently displaying classic Witbier character. Medium-low flocculation helps ensure classic Witbier haze. Alcohol tolerance: 12% .|
|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 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 .|
|St-Remy Abbey Ale||72-80||Med||18-24||This yeast strain isolated from a Belgian abbey is an excellent choice for Belgian-style beers, including abbey ales. This strain produces mixed fruity esters, while also highlighting malt aroma. This strain can be used at higher fermentation temperatures without becoming overly phenolic/spicy. Alcohol tolerance: >10% .|
|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 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% .|
|Wild Thing||Ontario||75-82||Med||25+||This wild Ontario ale yeast was isolated from an apple in a local orchard. Wild Thing produces distinct clove, spice, and subtle banana and apple fruit aroma. The taste is dry, spicy and clean. This yeast is most comparable to medium-attenuation Belgian-style ale yeasts. May require temperature ramping to 25C to ensure high attenuation. Alcohol tolerance: 9% .|
|GY003 Achouffe Belgian Ale||81-84 (medium gravity) 57-60 (7.7%+ abv)||Medium/Low||68-77||Abbey style yeast from the Belgian Ardennes. Produces aromatic, spicy clove-like notes and less fruity aromas than GY014. Moderately flocculant yeast that creates a slightly clearer beer than most Belgians.|
|GY007 Belgian Mix||79-81 (medium gravity) 67-70 (8.6%+ abv)||Low||68-77||A blend of Trappist Ale Yeast combine to create robust attenuation and a complex flavor profile. Spicy and fruity, this blend is slightly more flocculent than many Belgians. Good choice for High Gravity beers.|
|GY014 Scourmont Abbey Ale||79-81||Low||64-80||Classic Belgian yeast from one of the best known Trappist breweries. A fragrant yeast that produces delicious fruity aroma. Good choice for high gravity beers. Generally, the warmer this yeast is fermented the higher the level of fruit aromas produced.|
|GY015 Trappist Tripel||70-76||Low||66-74||Trappist Ale yeast from the mother of all Tripels. A balance of fruit and spice with a good malty finish provides a perfect complement for Belgian Ales, Dubbels and Tripels. Attenuation is on the slow side leaving more residual sweetness than our other Belgians. Less esters and phenolics than GY003 and GY014.|
|GY018 Saison 1||French Brewery||81-83 (medium gravity) 49-53 (6.2%+ abv)||Low||64-80||Traditional Saison yeast from a French craft brewery. Strong attenuator that produces a dry beer with a beautiful fragrance and the traditional Saison taste of fruit and pepper. Might be Saccharomyces cerevisiae var. diastaticus if this strain is the same as WY3711 .|
|GY027 Saison Yeast 2||Traditional Saison||79-83 (medium gravity) 44-47 (5.5%+ abv)||Low||64-80||Creates the fruity/spicy aroma traditional to the style. Warmer fermentation temps result in more intense flavor. Produces a tartness not found in most of our yeast and a slightly sweeter beer than GY018|
|GY028 Belgian Wit||74-79||Very Low||64-80||Traditional Belgian Wit yeast from one of the classic producers of the style. Creates a delicious spicy nose and a somewhat tart beer. Attenuates dry and leaves a slightly cloudy beer - very low flocculation.|
|GY047 Saison Blend||80-83 (medium gravity) 49-53 (6.2%+ abv)||Low||64-80||A blend of Saison yeast. This Blend is a super robust attenuator that produces a complex flavor profile of fruit and spice.|
|GY048 Golden Pear Belgian Ale||Duvel Moortgat Brewery||78-85||Low||65-80||Traditional yeast from the originator of the Belgian Golden Strong Ale style. Robust attenuation makes this yeast an excellent choice for low or high gravity Belgian and farmhouse style ales. Leaves a dry, slightly tart finish with an estery profile reminiscent of apple and pear with a subdued level of spicy phenolics. This yeast produces a moderate amount of sulfide that will dissipate quickly with conditioning.|
|GY077 Quebec Abbey Ale||Canadian Brewery||75-83||Medium||68-80||From one of the first breweries in North America to create a successful line of traditional Abbey style ales. This Belgian ale yeast creates a malt forward beer with subtle fruity esters and a very small amount of clove notes. Robust attenuation makes this yeast an excellent choice for low or high gravity beers where a slightly sweet malty finish is desired. Perfect for the Belgian Dubbel and Tripel styles.|
|A20 Citrus||Unicorn Dust ||74-78||Low||67-80||When you want to use Brett, but you don’t. Citrus cranks out orange and lemon aromas along with some tropical fruit. Use this strain at high temps for big ester production. As funky as saccharomyces gets. Same as WLP644 Sacch Trois .|
|B48 Triple Double||Westmalle ||74-78||Medium||65-77||The perfect strain for your classic abbey ales. Triple Double produces moderate esters with low to no phenolic characteristics. This strain is tried and true and works perfectly in a production environment. Keep an eye on Triple Double, it likes to sit on top of the wort throughout fermentation which may result in a slow fermentation. Similar to Wyeast 3787 and WLP530 .|
|B64 Napoleon||77-83||Low||65-78||This yeast is an insane wort attenuator. Napoleon will destroy the sugars in your saison and farmhouse beers – even the ones in which most brewer’s strains have no interest. When all is said and done, Napoleon produces very dry, crisp beers with nice citrus aromas. Yeast settling times can be long, usually requiring filtration for bright beers. Similar to Wyeast 3711 . Determined to be Saccharomyces cerevisiae var. diastaticus .|
|B45 Gnome||Achouffe ||72-76||Medium-High||65-75||The Gnome is the yeast for brewing Belgian inspired beers in a hurry. This strain is extremely flocculent and drops out of the beer quickly after fermentation. Gnome produces a nice phenolic character that goes well with hops, as well as with caramel and toffee flavors. Great for Belgian ales that need to be crystal clear without filtration. Similar to Wyeast 3522 .|
|B51 Workhorse||Kasteel ||72-77||Medium||65-75||Saison…no problem. Belgian stout, double… yep. Workhorse is the strain to use for a wide variety of brews. Super clean, this fast-attenuating strain has good flocculation characteristics. High alcohol tolerance makes this a great option for big Belgian beers. Similar to Wyeast 1581 .|
|B56 Rustic||Brasserie de Blaugies ||72-76||Medium||68-80||This unique yeast can be used in your saison, farmhouse ale, or other Belgian styles where high ester levels are important. Rustic typically produces a lot of bubblegum and juicy aromas that compliment complex maltiness. Similar to Wyeast 3726 .|
|B63 Monastic||Chimay ||74-78||Medium-Low||68-78||This strain is a beautiful yeast for fermenting abbey ales, especially quads; high alcohol and dark Belgian beers. Monastic will produce beers with a high level of phenolic character and esters. It can be slow to begin fermentation but will easily dry out high gravity worts. This strain is a low flocking strain, so expect it to stay suspended for a long time. Similar to Wyeast 1214 and WLP500 .|
|B53 Fish Finder||Orval ||74-78||Medium||65-73||The classic choice for a Belgian IPA. Fish Finder has a very mild phenolic character balanced with moderate fruitiness. Often used for primary and then finished with a secondary Brettanomyces yeast. Similar to WLP510 .|
|B44 Whiteout||Celis White/Hoegaarden ||72-76||Medium-Low||62-72||This is the strain for Belgian Wit style beers. Whiteout produces an excellent balance of spicy phenolic character and esters. Along with the necessary aromatics, this strain produces a significant amount of acidity which is perfect for wits and other light colored Belgian ales. Whiteout can be flocculent during fermentation, then become non-flocculent at the end. This may lead to slower than normal fermentation. Similar to Wyeast 3944 and WLP400 .|
|INIS-201 Belgian Monk Ale I||Monastery brewery in Southern Belgium||72-76||Medium||68-78||High alcohol tolerance and plum like notes create great dark Belgian beers.|
|INIS-202 Belgian Monk Ale II||73-77||Medium||65-75||High alcohol tolerance. Beer ferments clean with a full body and full malt flavor. Notes of dried fruit.|
|INIS-203 Belgian Monk Ale III||Monastery brewery||74-78||Medium||64-78||High alcohol tolerance. Isolated from a world class monastery brewery known for brewing high gravity ales with complex esters and phenols.|
|INIS-204 Belgian Monk Ale IV||73-77||Medium||65-75||High alcohol tolerance. Used to brew a beer with a dry and acidic finish but otherwise clean.|
|INIS-222 Belgian Gnome Ale||72-76||High||65-76||High alcohol tolerance. Distinctive, estery and phenolic profile.|
|INIS-225 Belgian American||Famous Belgian style brewery near Montreal||75-79||Medium||65-80||This yeast produces a beer that is dry with a low ester profile. Phenolics increase as this yeast is fermented at higher temperatures.|
|INIS-231 Belgian Gold||74-78||Low||64-80||Very high alcohol tolerance. Yeast used to brew a classic strong ale in the Belgian tradition. High alcohol tolerance with mild phenols and fruity esters.|
|INIS-241 Belgian Wit I||72-76||Medium||64-74||High alcohol tolerance. Used to brew wit style beer. Notes of pear, apple, stone fruit, and a slight acidity/tartness in the finish. Very top heavy.|
|INIS-242 Belgian Wit Devil||72-76||Medium||62-75||High alcohol tolerance. Similar to Belgian Wit I but with more phenols and clove. Very top heavy requiring a lot of extra space in the fermenter to prevent pushing all of the yeast out of the blow off tube.|
|INIS-251 French Ale||68-75||Med-High||63-73||This strain produces a clean beer that complements malt with lower ester production than traditional Belgian strains. Excellent yeast choice for a Biere de Garde and specialty beer. Might be Saccharomyces cerevisiae var. diastaticus .|
|INIS-291 Farmhouse: Saison||74-79||Medium||70-95||High alcohol tolerance. A dynamic yeast that produces a wide range of phenols and esters. Notes of strawberry, hay, and spice. Leaves the finish slightly tart and with an excellent mouth feel.|
|INIS-292 Saison: Belgian I||76-80||Low||70-95||High alcohol tolerance. Traditional saison strain isolated from a premier Belgian Brewery. Fruity, spicy, slightly tart, and leaves the beer dry. Known for stalling towards the end of the fermentation around 5-7 plato, but with additional heat and time will finish.|
|INIS-293 Saison: Belgian II||78-85||Medium||68-78||Medium alcohol tolerance. Strain is more fruity than Belgian I but from a similar source. Rumored to be a part of a mixed fermentation. This isolated strain is more reliable than Saison: Belgian I but with less depth.|
|INIS-294 Saison: French||77-83||Low||77-83||High alcohol tolerance. A saison yeast that produces more phenols than the Belgian Saison strains. Notes of pepper and citrus along with other spices. Leaves behind a pleasant mouthfeel in the beer despite being highly attenuative. It is less likely to stall than the Belgian Saisons.|
|INIS-295 Saison: Phantom||74-79||Low||70-84||This strain produces a saison with subtle spiciness and moderate ester production. The beer finishes dry and tart with no sluggishness like other Belgian Saison yeast.|
|INIS-296 Saison: Walloon||80-88||Medium||72-80+||This strain produces mild acidity, subtle spicy phenols and some light “funk”. Wide range of phenol and ester production based on fermentation temperature.|
|INIS-298 Saison: Baron||France||70-80||Medium||70-80||A true Bier-de-Garde yeast from France. Yeast produces a briny flavor and notes of white pepper and straw.|
|INIS-317 English Ale VII||65-69||Medium||80+||This strain produces a malty beer that is slightly fruity for lower gravity beers. Very high alcohol tolerance makes this a good yeast choice for beers above 10% ABV. INIS-317 English Ale VII has been identified using polymerase chain reaction (PCR) to contain the glucoamylase gene (STA1), which can be an indicator of Saccharomyces cerevisiae var. diastaticus. As such, INIS-317 has the ability to utilize some dextrins which are unfermentable to most species of S. cerevisiae, and thus achieve a very high level of attenuation. However, INIS-317 is not considered a contaminant and will not over attenuate finished beer when a high level of attenuation is expected .|
|INIS-491 Saison: French||77-83||Low||65-77||A saison strain that produces more phenols than the Belgian Saison strains. Notes of pepper and citrus along with other spices. This yeast leaves behind a pleasant mouthfeel in the beer despite being highly attenuative. It is less likely to stall than the Belgian Saison strains. This strain has been identified using polymerase chain reaction (PCR) to contain the glucoamylase gene (STA1), which can be an indicator of Saccharomyces cerevisiae var. diastaticus. As such, INIS-491 has the ability to utilize some dextrins which are unfermentable to most species of S. cerevisiae, and thus achieve a very high level of attenuation. However, INIS-491 is not considered a contaminant and will not over attenuate finished beer when a high level of attenuation is expected .|
|JY029 - Belgian Wit I||Hoegaarden||70-77||Low||63-76||Spicy and phenolic, with a nice estery finish. Great for witbier, Grand Cru-style wit and specialty beers. Belgian Styles, mainly Belgian Wit and Grand-Cru, but does well in Blonde, Belgian Tripel and Specialty|
|JY031 - Nova Ale Yeast||Ashburn, Virginia||71-80||Very low||68-85||A true local strain! Isolated in Ashburn, Virginia in 2008. The first native Virginia yeast used in commercial beer since prohibition (Farmwell Wheat and Native Son, both Lost Rhino Brewing Company). Higher fermentation temperatures are preferred with this strain. Producer of high levels of fruitiness above 26 ºC (80 ºF), earthy notes are present at lower fermentation temperatures (20 ºC, 68 ºF). Since it is a wild Saccharomyces cerevisiae strain one can expect drift when repitched for many generations.|
|JY056 - Poperinge Saison||Famous Brasserie in Southern Belgian/Northern France region.||79-85||Very low||65-77||Aggressive, attenuative and outspokenly estery and peppery. Great for Saison and Farmhouse style beers at higher temperatures, in the lower range good for more traditional Belgian styles. Good to finish off a beer that has problems fermenting with another yeast.|
|JY104 - Benedict Abbey||Small brewery in Flemish Brabant, Belgium.||75-80||Low||68-77||JY104 was handed to Jasper Akerboom when he toured some small microbreweries in the Netherlands and Belgium by a friendly microbrewer. This strain originally belonged to a small brewery in Flemish Brabant in Belgium. The brewery was acquired by a large macrobrewery, and management decided to do away with this precious yeast. Fortunately passionate homebrewers and beer enthusiasts were able to keep some of the yeast going and you can use it now as well! This strain ferments fast, and aggressive. It can be under pitched easily, and attenuates deep. Great esters and phenols, can be slightly peppery. Flocculates slow, but can withstand spunding without a problem. This yeast is great for lighter colored Belgians, but is great for darker Belgians as well. This strain has not been fully characterized, so we do not know what gravity this yeast will ferment. We do know that it attenuates very well, and the initial tests have indicated that can ferment easily to 10% ABV.|
|JY110 - NOVA Ale Yeast 2||Northern Virginia||75-80||Low||75-100||This yeast differs from JY031 Nova Ale Yeast 1 by being slight more toned down in the aromatics and flavor department. Isolated in Northern Virginia, this strain is truly local. Power to VA! Since this is a new variety of Saccharomyces cerevisiae, this strain has not been fully characterized yet. Feel free to share your information with us if you use this strain! This strain will be perceived slightly Belgianesque, but at lower fermentation temperatures will be lower in aromatics. Can slow down when temperature is low. Likes it warm.|
|JY146 - Protocetid Ale||Calvert Marine Museum in Solomons, MD.||>80||Very low||max 90||This yeast is the famous strain isolated from the Calvert Marine Museum in Solomons, MD. This strain was isolated from Protocetid bone, discovered by Jason Osborne, the president and co-founder of Paleo Quest, a non-profit citizen-science organization for the advancement of the sciences of paleontology and geology through material contributions to museum collections, field exploration, scientific publication and education. This yeast is used for the famous Lost Rhino Brewing Company Bonedusters Ale. This yeast is hard to work with, it has the tendency to stop fermenting for a week after 30% attenuation, after which it picks back up and finishes out. Not for the faint of heart! Expect a Belgian character, with some tartness. Keep the desired ABV low during your recipe development, this strain is not suited for high-gravity worts. Finishes crisp and fruity, with a pleasant fizz.|
|BB 3||Spontaneous capture||70-82||68-78||This is an interesting strain as it has hints of stone fruit as well as a Saison like quality to it lending citrus notes. Commercial pitches only .|
|MYJuicy||Maine Maple Tree||70-85||65-80||Wild Sacc strain caught and isolated from a maple tree in Maine. Produces lots of tropical fruit esters. Commercial pitches only .|
|Infectious Behavior||80-100||65-80||Currently this species is a hot topic amongst infections in breweries. As it has the ability to metabolize starches and complex sugars, which most primary yeast fermentation leaves behind. We isolated this out of an infected beer and found it to have very Saison like qualites. Commercial pitches only .|
|Sacc Full of Fruit||Wild Capture||70-80||65-78||Stone fruit galore! This Sacc strain creates massive stone fruit notes such as peach, plum and cherry. It works very well for West Coast IPAs, NEIPAs, and a bunch of other styles! We especially like this when in a beer double dry hopped with Belma and Mosaic. Commercial pitches only .|
|Citrus King||Wild Capture||70-82||62-80||This particular Sacc c strain produces huge notes of citrus peels and a hint of tropical fruit. It pairs extremely well with the citrus forward new age hops as well as many of the older varieties. We find its perfect for citrusy NE IPAs. This strain also tends to keep the beer hazier given enough protein is also in the wort. Commercial pitches only .|
|M21 Belgian Wit||High||Low||64-77||A traditional top-fermenting yeast that has a good balance between fruity esters and warming spice phenolics. The yeast will leave some sweetness and will drop bright if left long enough. Suitable for Witbier, Grand Cru, Spiced Ales and other specialty beers.|
|M29 French Saison Ale (previously M27) ||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 . Confirmed to be Saccharomyces cerevisiae var. diastaticus .|
|M31 Belgian Tripel||Very High||Med||64-82||Provides a fantastic complex marriage of spice, fruity esters, phenolics and alcohol. It is also very attenuative with a high alcohol tolerance making it perfect for a range of Belgian styles. Suitable for Belgian Tripel and Trappist style beers.|
|M41 Belgian Ale||Very High||Med||64-82||Spicy and phenolic, this yeast emulates the intensity and complexity of some of the best monastic breweries in Belgium. High attenuation and alcohol tolerance allow you to brew a huge range of Belgian beers. Suitable for Belgian Strong Golden and Belgian Strong Dark Ales.|
|M47 Belgian Abbey Yeast||High||High||64-77||Moderately alcohol tolerant with fewer phenols than Belgian Ale, this yeast is exceptionally fruity with hugely complex esters and is highly flocculant.|
|Abbey Ale C - (OYL-018)||74-78||Medium-Low||68-78||From a famous Trappist brewery, this yeast produces the distinctive fruitiness and plum characteristics. Excellent yeast for high gravity beers, Belgian ales, Dubbels and Tripels. Compares to WLP500 and WY1214. Commercial pitches only.|
|Belgian Ale A (OYL-024)||72-85||High||65-78||Versatile strain for the production of classic Belgian style ales. This strain produces a beautiful balance of delicate fruit esters and subtle spicy notes, with neither one dominating. Unlike many other Belgian style strains, this strain is highly flocculent and results in bright beers. Compares to Compares to WLP550 and WY3522. Available to homebrewers.|
|Belgian Ale D (OYL-019)||74-78||Low||64-80||The best choice for brewing golden strong ales. This alcohol tolerant strain will produce a complex ester profile balanced nicely with subtle phenolics. Malt flavors and aromas will remain even with a well attenuated dry, tart finish. It may continue to produce CO2 for an extended period after packaging or collection. Compares to WLP570 and WY1388. Commercial pitches only.|
|Belgian Ale DK (OYL-049)||73-80||Medium||67-70||Clean Belgian type ale yeast. Good for Belgian style pale ales and amber ales. Biscuity, ale-like aroma with accentuated hop flavor and bitterness. Slight sulfur will be produced during fermentation, which can give the yeast a lager-like flavor profile. Compares to WLP515. Commercial pitches only.|
|Belgian Ale O (OYL-046)||74-80||Medium||66-72||A Trappist style ale yeast. Produces dry beer with slight acidic finish, but cleaner than OYL-018 and OYL-028. Good choice for high gravity beers, Belgian ales, Dubbels and Tripels. Compares to WLP510. Commercial pitches only.|
|Belgian Ale R (OYL-020)||73-82||Medium||65-75||Great choice for use in Belgian dark strong ales. This strain has a relatively “clean profile” which allows a rich malt and distinctive ethanol character to shine. Delicate dried fruit esters can be produced when used at higher fermentation temperatures or in a high gravity wort. Compares to WLP540 and WY1762. Commercial pitches only.|
|Belgian Ale W (OYL-028)||74-78||Medium||64-78||Classic strain for brewing Belgian Dubbel or Belgian Tripel. This strain produces a nice balance of complex fruity esters and phenolics, making it desirable for use in other Belgian style ales as well. A flocculent, true top cropping yeast (additional headspace is recommended), that will work over a broad temperature range. Makes a great Belgian style “house” strain. Compares to WLP530 and WY3787. Available to homebrewers.|
|Belgian Dark Ale A (OYL-040)||74-79||Medium||65-80||Belgian ale yeast that is a high acid producer with balanced ester and phenol production. High alcohol tolerance. Spicy, tart, and dry on the palate with a very complex finish. Compare to WY3822. Commercial pitches only.|
|Belgian Saison I (OYL-027)||76-80||Low||70-95||Most widely used farmhouse ale yeast. A traditional yeast that is spicy with complex aromatics, including bubble gum. It is very tart and dry on the palate with a mild fruitiness. Will yield a crisp, mildly acidic finish that will benefit from elevated fermentation temperatures. This strain is notorious for a rapid and vigorous start to fermentation, only to stick around 1.035 S.G. Fermentation will finish, given time and warm temperatures. Warm fermentation temperatures, at least 90°F (32°C), or the use of a secondary strain can accelerate attenuation. Compares to WLP565 and WY3724. Commercial pitches only.|
|Belgian Saison II (OYL-042)||74-79||Medium||70-84||This strain produces complex esters balanced with earthy/spicy notes. Slightly tart and dry with a peppery finish. A perfect strain for Farmhouse ales and Saisons. Compares to WY3726. Commercial pitches only.|
|Belgian Wheat (OYL-029)||72-76||Medium||64-74||Produces beers with moderate esters and minimal phenolics. Apple, bubblegum, and plum-like aromas blend nicely with malt and hops. This strain will finish dry with a hint of tartness. Compares to WY3942. Commercial pitches only.|
|Biere de Garde (OYL-039)||74-79||Low||70-84||Ferments well with low to moderate ester production and subtle spiciness. Malty and full on the palate with initial sweetness. Finishes dry and slightly tart. Compares to WY3725. Commercial pitches only.|
|French Saison (OYL-026)||77-83||Low||65-77||Versatile strain that produces Saison or farmhouse style beers as well as other Belgian style beers that are highly aromatic (estery), peppery, spicy and citrusy. This strain enhances the use of spices and aroma hops, and is extremely attenuative but leaves an unexpected silky and rich mouthfeel. This strain can also be used to re-start stuck fermentations or in high gravity beers. Compares to WY3711. Determined to be Saccharomyces cerevisiae var. diastaticus . Commercial pitches only.|
|Grand Cru (OYL-023)||72-76||Low||63-76||Widely used strain in the production of Witbier, Grand Cru, sweet mead and cider. Produces spicy phenolics which are balanced nicely by a complex ester profile. The subtle fruit character and dry tart finish will complement wheat malt, orange peel and spice additions typical of Wits. Compares to WLP720 and WY3463. Commercial pitches only.|
|Saisonstein's Monster (OYL-500)||80-90||Low||65-78||The first in our line of hybrid strains. This strain is a genetic hybrid resulting from the mating of strains OYL-026 and OYL-027, created by and available exclusively from Omega Yeast. Less phenolic and more fruit character than 026. Exhibits some of the bubble gum character of 027. Omega Yeast Labs Exclusive. This might be a hybrid of S. boulardii and S. cerevisiae var. diastaticus . Available to homebrewers.|
|Wit (OYL-030)||72-76||Medium||62-75||Produces a complex flavor profile dominated by spicy phenolics with low to moderate ester production. It is a great strain choice when you want a delicate clove profile not to be overshadowed by esters. It will ferment fairly dry with a slightly tart finish that compliments the use of oats, malted and unmalted wheat. This strain is a true top cropping yeast requiring full fermenter headspace of 33%. Compares to WLP400 and WY3944 vs Omega Yeast Labs Exclusive. Commercial pitches only.|
|MIP-211 Belgian Ale I||Mid - High 70's||Med||68-78||Produces subtle banana esters .|
|MIP-212 Belgian Ale II||Mid - High 70's||Med||68-78||Slightly phenolic and works best in higher alcohol beer .|
|MIP-213 Belgian Ale III||Mid - High 70's||Med||68-78||Produces stone fruit esters such as plumb; recommended for dubbels and quads .|
|MIP-220 Belgian Dwarf Ale||Mid - High 70's||High||68-78||Produces a wide range of esters and phenols depending on fermentation temperature. It's a versatile yeast and ferments fast .|
|MIP-231 Belgian Wit Ale I||Mid 70's||Med||65-74||Produces pear and red apple esters .|
|MIP-232 Belgian Wit Ale II||Mid 70's||Med||63-74||Produces clove/white pepper phenols .|
|MIP-310 Daffodil Saison||Somewhere in France||Low 70's||Med||63-74||Produces a minerality, tastes dry .|
|RBY41 French Saison||77-83||Low||65-75||Determined to be Saccharomyces cerevisiae var. diastaticus . Might be the same strain as WY3711.|
|RBY58 - Fantome Saison Clone #1||Fantome||70-80||Low||75-85|
|RVA 261 Saison I||Dupont||65-75||Med||75+||fruity, bubblegum esters with all the spice and pepper that makes Saison so appealing|
|RVA 262 Saison II||75-82||Med||67-77||French origin, this strain produces a bit less of the fruity, bubblegum esters with less spice and pepper then RVA 241. Determined to be Saccharomyces cerevisiae var. diastaticus . Might be the same strain as WY3711|
|RVA 263 Ghost Ale||Fantome||74-84||Med||65-80||Ripened fruit esters and a crisp earthy finish can be achieved even at lower temperatures with this Belgian farmhouse strain|
|RVA 806 Lickinghole Creek Ale||Virginia’s LHCB farm||78-85||Med||68-74||Citrus esters, a nose of sweet honey and a dash of phenolic spice, this strain will complement a variety of dry Belgian style beers. We highly recommend this strain for Belgian triple and Saison.|
|Demonical||Popular yeast strain from a well-known Belgian brewery. Because of its ester-dominated fermentation profile, this yeast strain is often used in strong Belgian ales. Other beer styles where this yeast strain can be used are Belgian-style IPA, Belgian blond and Tripel.|
|Trappist O||Relatively clean Belgian yeast from a Trappist brewery in the Ardennes. A good choice for most Belgian ales, but especially strong pale Belgian ales. In combination with Brett I, this strains can be used for brewing Belgian specialty ales.|
|Wheat I||Belgian Wit yeast from a brewery in West Flanders.|
|Castle||Alcohol tolerant yeast strain suitable for strong and sweet ales. This yeast strain originates from a West Flemish brewery.|
|Gnome||Yeast strain from a brewery in the Belgian Ardennes. Very versatile strain that fits most Belgian ale styles because of its balanced fermentation profile.|
|Pixie||Slightly phenolic and spicy yeast strain from West Flanders. This is a versatile yeast strain that fits both malty and hoppy beers.|
|P1 Musserweissen||Dwarf Peach (Clemson, SC)||78.7%||Low||Use for Wit, Heffe, Saison, Kölsch. "Medium" acidity. Banana, peach esters; citrus peel and clove phenolics. 4-6 weeks in primary. Hazy, notes of champagne .|
|N3 Native Cider||Nectarine (South Carolina)||83.2%||High||Use for light Belgian ales, cider, wine. "No acidity". Apple cider esters; light pepper spice phenolics. 3-4 weeks in primary .|
|B3 Farmhouse Ale||Blueberry (Clemson, SC)||79.3%||Low||Use for saison, farmhouse ales. "Medium acidity". Tart esters; straw spice phenolics. 4-6 weeks in primary. It produces notes of straw and spice - enough to pique the palate but not enough to offend. It even produces enough acid to leave a noticeable tartness in the beer. It will leave the beer hazy with yeast at the end of its 4-6 week fermentation .|
|HS2 New Abbey Ale||Honeysuckle (Walland, TN)||78%||Medium||Use for Belgian and Abbey type ales. "Low acidity". Red wine esters; cracked pepper corn phenolics. 3-4 weeks in primary. Full flavor and complex. .|
|N1 Native Strong Ale||Nectarines (Clemson, SC)||High||N1 was one of the first wild yeasts we ever captured and a good portion of why we fell in love with wild yeast. N1 is our workhorse yeast, finishing semi-dry and clean with a hint of champagne. It flocculates well after 3-4 weeks. Good for pale ales, strong ales, mead and cider.|
All single and mixed blends will contain ~80 billion cells per homebrew sized vial .
|Saison Blend||80||Med||70-78||Blend of 2 yeast strains, Flavors of pepper, grapefruit, Orange zest|
|Wallonian Farmhouse||81-88||Med||68-78||Slight earthy funk and tart character to the beer; we recommend controlling the dryness by adjusting the mash temperature or adding malts or adjuncts to the mash tun that will lend some body and residual sweetness to the beer. Although it can be fermented at lower temps, for full flavor it is recommended to start fermentation in the 70°F's, and let it free-rise to the low to mid 80°F's . Determined to be Saccharomyces cerevisiae var. diastaticus .|
|Wallonian Farmhouse II||80-82||Med-Low||68-80||This is a single strain of Saccharomyces cerevisiae isolated from the same source as our Wallonian Farmhouse strain, a well-known brewery hailing from the Walloon region of Belgium. Slightly less attenuative and exhibiting a more restrained phenolic and expressive ester profile than our original Wallonian Farmhouse, this yeast is a great choice for any classic saison style beer in which a balance of fruitiness and rustic farmhouse character is desired. Wallonian Farmhouse II works very well in conjunction with Brettanomyces owing to its robust and complex ester and phenol profile, so well that it has the honor of being the dominant saison strain in our new Saison/Brettanomyces Blend II culture .|
|Wallonian Farmhouse III||80-82||Med-Low||68-80||This is a single strain of Saccharomyces cerevisiae isolated from a well-known brewery hailing from the Walloon region of Belgium. This strain is as attenuative as our original Wallonian Farmhouse and exhibits a more balanced profile of ester and phenols. This yeast is similar to a classic saison strain offered by many other yeast manufacturers, without the slow/low attenuation and stalling issues often observed in those cultures. Wallonian Farmhouse III works very well in conjunction with Brettanomyces owing to its balanced and complex ester and phenol profile .|
|Saison Blend II||80-86||Med||68-80||This saison blend is the Saccharomyces portion of our Farmhouse Sour Ale, available to you as a result of popular demand from the commercial brewing crowd. This combination of Saccharomyces strains embodies the balanced fusion of the two foremost saison flavor/aroma characters, fruitiness and earthiness. Each Saccharomyces strain in this blend produces flavor compounds that serve as the yin to the other's yang, and the result is an exceptionally complex yet balanced flavor and aroma profile. One strain will serve to create an ester profile of grapefruit and orange zest, while the other will produce a mild earthiness and spiciness. Close your eyes while drinking a beer fermented with this blend, and you'll feel like you're laying on freshly turned earth in an old citrus grove. Contains a strain that is determined to be Saccharomyces cerevisiae var. diastaticus .|
|Dry Belgian Ale||85-100||Med-High||68-74||Dry Belgian Ale is single strain of Saccharomyces cerevisiae isolated from a unique golden strong ale. The profile is a complex and balanced mix of apple, pear and light citrus fruit with some mild spicy and peppery notes. The apparent attenuation of this strain ranges anywhere from 85-100%, depending upon the mash profile and the grist composition. For a yeast that's as dry as it is, it creates beers with a surprising amount of balance even without the use of specialty grains or adjuncts. While we haven't completed our own tests in house, this yeast is used at the brewery from which it was isolated to make big beers that are in the neighborhood of 12-16% ABV and sufficiently dry. Use Dry Belgian Ale as a primary fermenter in any big Belgian beer, or to unstick that pesky stuck fermentation. Determined to be Saccharomyces cerevisiae var. diastaticus .|
|Northeastern Abbey||77-81||Med-Low||68-73||This yeast was isolated from a beer crafted by a well-known producer of Belgian-style ales in the Northeastern United States. This yeast produces a very mild spiciness and earthy flavor and aroma which is complemented by a subtle but magnificent array of fruity esters, including pear and light citrus fruit. The brewery from which this strain was isolated uses it in a very versatile manner across an array of Belgian styles. We prefer using this yeast for any and all light Belgian beers, including Wit, Belgian Pale and Belgian Blond, in addition to any experimental fruit beers in which a more unique and robust flavor and aroma profile is desired. Expect this yeast to produce a large, thick krausen.|
|Funktown Pale Ale||78-80||Medium-Low||68-74||Funktown Pale Ale is a blend of our Vermont Ale strain and a unique strain of Brettanomyces that is well suited for primary fermentation Saccharomyces "Bruxellensis" Trois. The combination of the citrus/peach esters from the Vermont Ale strain and the very light funk and pineapple/mango esters from the Brettanomyces produces a unique flavor and aroma profile that is fruit-forward. Expect this blend to finish drier than the Vermont Ale. We recommend following a similar fermentation scheme as is used for the Vermont Ale, fermenting at 67-69 ºF for 3-4 days, and then raising the temperature to 72 ºF until a stable gravity is reached. Contains a strain that is determined to be Saccharomyces cerevisiae var. diastaticus .|
|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 .|
- 1.5 to 3.0 billion per milliliter; homebrew PurePitch® packages contain 60-120 billion cells. See White Labs FAQ for an explanation on varying cell counts in PurePitch® packages, and the public Yeastman database.
- See White Labs list of Belgian yeast strains and characteristics, including phenols/spiciness.
- See The WL Vault, which contains many non-conventional yeasts and bacteria.
|WLP072 - French Ale||69-75||Med-High||63-73||Clean strain that complements malt flavor. Low to moderate esters, when fermentation temperature is below 70°F. Moderate plus ester character over 70°F. Low diacetyl production. Good yeast strain for Biere de Garde, blond, amber, brown ales, and specialty beers. Seasonal Availability: May - Jun.|
|WLP400 - Belgian Wit Ale||Hoegaarden/Celis ||74-78||Low-Med||67-74||Slightly phenolic and tart, this is the original yeast used to produce Wit in Belgium.|
|WLP410 - Belgian Wit II Ale||Moortgat Brouwerij (via Ommegang?) ||70-75||Low-Med||67-74||Less Belgian-like phenolics than WLP400 and more spicy. Will leave a bit more sweetness, and flocculation is higher than WLP400. Use to produce Belgian Wit, spiced Ales, wheat Ales, and specialty Beers.|
|WLP500 - Monastery Ale||Chimay ||75-80||Low-Med||65-72||From a Belgian monastery where monks traditionally made beer, this yeast produces the distinctive fruitiness and plum characteristics. Excellent yeast for high gravity beers, Belgian ales, Dubbels and Tripels.|
|WLP510 - Bastogne Belgian Ale||Orval ||74-80||Med||66-72||A high gravity, Trappist style ale yeast. Produces dry beer with slight acidic finish. More ‘clean’ fermentation character than WLP500 or WLP530. Not as spicy as WLP530 or WLP550. Excellent yeast for high gravity beers, Belgian ales, Dubbels and Tripels.|
|WLP515 - Antwerp Ale||De Koninck ||73-80||Med||67-70||Clean, almost lager like Belgian type ale yeast. Good for Belgian type pales ales and amber ales, or with blends to combine with other Belgian type yeast strains. Biscuity, ale like aroma present. Hop flavors and bitterness are accentuated. Slight sulfur will be produced during fermentation, which can give the yeast a lager like flavor profile. Seasonal Availability: Nov - Dec.|
|WLP530 - Abbey Ale||Westmalle ||75-80||Med-High||66-72||Used to produce Trappist style beers. Similar to WLP500, but is less fruity and more alcohol tolerant (up to 15% ABV). Excellent yeast for high gravity beers, Belgian ales, Dubbels and Tripels.|
|WLP540 - Abbey IV Ale||Rochefort ||74-82||Med||66-72||An authentic Trappist style yeast. Use for Belgian style ales, Dubbels, Tripels, and specialty beers. Fruit character is medium, in between WLP500 (high) and WLP530 (low). This strain benefits from extra oxygenation. Seasonal Availability: Jul - Aug.|
|WLP545 - Belgian Strong Ale||78-85||Med||66-72||From the Ardennes region of Belgium, this classic yeast strain produces moderate levels of ester and spicy phenolic character. Typically results in a dry, but balanced finish. This yeast is well suited for Belgian dark strongs, Abbey Ales, and Christmas beers.|
|WLP550 - Belgian Ale||Achouffe ||78-85||Med||68-78||Saisons, Belgian Ales, Belgian Reds, Belgian Browns, and White beers are just a few of the classic Belgian beer styles that can be created with this yeast strain. Phenolic and spicy flavors dominate the profile, with less fruitiness then WLP500.|
|WLP565 - Belgian Saison||Brasserie Dupont (Saison Dupont) ||65-75||Med||68-75||May stall, use at higher temps to prevent. Considered the "Dupont" strain.|
|WLP566 - Saison II||Vieille Provision Saison Dupont  and Brasserie de Blaugies||78-85||Med||68-78||Saison strain with more fruity ester production, Fast Fermenter.|
|WLP568 - Belgian Ale Yeast Blend||70-80||Med||70-80||Belgian style ale and Saison strains. The strains work in harmony to create complex, fruity aromas and flavors. Yeast strain encourages complete fermentation in a timely manner. Phenolic, spicy, earthy, and clove like flavors are also created.|
|WLP570 - Belgian Golden Ale||Duvel (Moortgart) via McEwans ||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 . Determined to be Saccharomyces cerevisiae var. diastaticus .|
|WLP575 - Belgian Style Ale Yeast Blend||WLP500, WLP530, WLP550 ||74-80||Med||68-75||A blend of Trappist type yeast (2) and one Belgian ale type yeast. This creates a versatile blend that can be used for Trappist type beer, or a myriad of beers that can be described as 'Belgian type'.|
|WLP585 Belgian Saison III||70-74||Med||68-75||Produces beer with a high fruit ester characteristic, as well as some slight tartness. Finishes slightly malty, which balances out the esters. Low levels of clove phenolics. Great yeast choice for a summer Saison that is light and easy-drinking. Seasonal Availability: Jul - Aug. Reported by Richard Preiss of Escarpment Laboratories that WLP585 has the STA1 gene that codes for Saccharomyces cerevisiae var. diastaticus, but reported that it takes weeks before it hyper-attenuates |
|WLP590 French Saison Ale||73-80||Med||69-75||Unique yeast strain producing farmhouse-style beers with a phenolic “bite” and moderate ester compounds. Producing a cleaner aroma profile than other farmhouse styles, this yeast is versatile and highly attenuating. Seasonal Availability: May - Jun. Determined to be Saccharomyces cerevisiae var. diastaticus .|
|WLP644 Saccharomyces "Bruxellensis" Trois||85%+||Low||70-85|| Medium-High alcohol tolerance. This Belgian strain produces a slightly tart beer with delicate characteristics of mango and pineapple. Can also be used to produce effervescence when bottle-conditioning. Formally named Brettanomyces bruxellensis Trois, it was re-classified to be Saccharomyces, and probably S. cerevisiae . White Labs classifies this as a "wild Saccharomyces" . Trois cannot ferment lactose . It does not produce significant amounts of acetic or lactic acid, even under aerobic conditions . Therefore if acid (lactic or acetic) is found in a Trois beer, contamination would be the cause. It also does not produce phenols (POF-), but does produce higher amounts of esters than most strains of S. cerevisiae  |
|WLP700 Flor Sherry Yeast||80-100 (may not be accurate)||70-100||15%+ ABV alcohol tolerance. Report by Johnny Horn for 100% WLP700 in the following characteristics: aroma: slightly savory, slight worcestershire sauce, earthy, cidery. Flavour: sweet nutty caramel, light acidity, honey, apple, brown sugar, strawberry/cherry, dry woody, slightly thin mouthfeel. Has its own odd (but pleasant) character and complexity. Final pH was 3.5, which might indicate a blend with lactic acid bacteria (1g/l aged Fuggles at 60 mins, and 1g/l aged Fuggles at 10 mins). Pitch was 1.0 (M cells / ml / ° P) at 19C and fermentation chamber was set to 21-22C for duration. Final gravity was stable at 1.024 from 1.065 at about 4 weeks, indicating that the advertised attenuation may not be accurate . Can be a slow fermenter on its own. See also the WL FAQ.|
|WPY125||Oak tree in Red River Gorge, KY||Sweet and floral aromas are produced by this strain, and it yields a typical Belgian phenolic flavor .|
|1214 - Belgian Abbey™||74-78||Med-Low||68-78||A widely used and alcohol tolerant Abbey yeast that is suitable for a variety of Belgian style ales. This strain produces a nice ester profile as well as slightly spicy alcohol notes. It can be slow to start; however, it attenuates well.|
|1388 - Belgian Strong Ale™||(Suspected) Duvel/McEwans ||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 Saccharomyces cerevisiae var. diastaticus .|
|1762 - Belgian Abbey II™||73-77||Med||65-75||An excellent yeast strain for use in Belgian dark strong ales. This strain has a relatively “clean profile” which allows a rich malt and distinctive ethanol character to shine. Delicate dried fruit esters can be produced when used at higher fermentation temperatures or in a high gravity wort.|
|3463 - Forbidden Fruit™||(Suspected) Hoegaarden Verboden Vrucht ||72-76||Low||63-76||A widely used strain in the production of Witbier and Grand Cru. This yeast will produce spicy phenolics which are balanced nicely by a complex ester profile. The subtle fruit character and dry tart finish will complement wheat malt, orange peel and spice additions typical of Wits. Available from April through June 2017.|
|3522 - Belgian Ardennes™||72-76||High||65-76||One of the great and versatile strains for the production of classic Belgian style ales. This strain produces a beautiful balance of delicate fruit esters and subtle spicy notes, with neither one dominating. Unlike many other Belgian style strains, this strain is highly flocculent and results in bright beers.|
|3538 - PC Leuven Pale Ale||75-78||High||65-80||This vigorous top fermenting Belgian style strain produces a distinct spicy character along with mild esters. Phenolics developed during fermentation may dissipate with conditioning. 3538 is an excellent choice for a wide variety of Belgian beer styles. Private Collection for Spring 2015 (available April-June 2015).|
|3711 - French Saison||77-83||Low||65-77||Peppery, spicy and citrusy. This strain enhances the use of spices and aroma hops, and is extremely attenuative but leaves an unexpected silky and rich mouthfeel. See this MTF thread for fermentation tips. Determined to be Saccharomyces cerevisiae var. diastaticus . This strain has been rumored to originate from the Brasserie Thiriez brewery , however, Daniel Thiriez claims that his brewery's strain of yeast is not the same as WY3711 .|
|3724 - Belgian Saison™||Dupont||76-80||Low||70-95|| It is very tart and dry on the palate with a mild fruitiness. Expect a crisp, mildly acidic finish that will benefit from elevated fermentation temperatures. Notorious for a rapid start, only to stick. Fermentation will finish, at least 90°F. The same or very similar to the "Dupont" strain.
This strain was sequenced by Lance Shaner of Omega Yeast Labs as possibly being the species S. boulardii; it is not known if other labs who offer the "Dupont" strain offer the same isolate because bottles of Dupont saison have reportedly been found to have multiple and varying strains over time . Determined to be Saccharomyces cerevisiae var. 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 Saccharomyces cerevisiae var. 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 Saccharomyces cerevisiae var. 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 Saccharomyces cerevisiae var. diastaticus . Available from April through June 2016.|
|3787 - Trappist High Gravity™||(Suspected) Westmalle ||74-78||Med||64-78||A classic strain for brewing Belgian Dubbel or Belgian Tripel. This Abbey strain produces a nice balance of complex fruity esters and phenolics, making it desirable for use in other Belgian style ales as well. A flocculent, true top cropping yeast (additional headspace is recommended), that will work over a broad temperature range. This strain makes a great Belgian style “house” strain.|
|3822 - Belgian Dark Strong Ale™||74-79||Med||65-80|| Oud Bruin/Flanders Brown, Fruit beers, Belgian Golden and Dark Strong Ales, Kriek and Framboise, Belgian Specialty Ale
Profile: 3822-PC is a unique Saccharomyces strain which produces spicy, phenolic and distinctly tart aromas and flavors, which can be increased through warmer fermentation temperatures. Very tart and dry on the palate, complemented well by blending with fruit. Available from April through June 2016.
|3864 - Canadian/Belgian Ale™||74-79||Med||65-80||This alcohol tolerant strain produces complex and well-balanced Belgian Abbey style ales. Banana and fruit esters are complemented nicely with mild levels of phenolics and hints of acidity. Ester levels may be elevated by increasing gravity and fermentation temperatures. May produce some sulfur at cool fermentation temperatures. Determined to be Saccharomyces cerevisiae var. diastaticus . Available from April through June 2016.|
|3942 - Belgian Wheat™||(Suspected) De Dolle ||72-76||Med||64-74||Isolated from a small Belgian brewery, this strain produces beers with moderate esters and minimal phenolics. Apple, bubblegum and plum-like aromas blend nicely with malt and hops. This strain will finish dry with a hint of tartness.|
|3944 - Belgian Witbier™||72-76||Med||62-75||This versatile Witbier yeast strain can be used in a variety of Belgian style ales. This strain produces a complex flavor profile dominated by spicy phenolics with low to moderate ester production. It is a great strain choice when you want a delicate clove profile not to be overshadowed by esters. It will ferment fairly dry with a slightly tart finish that compliments the use of oats, malted and unmalted wheat. This strain is a true top cropping yeast requiring full fermenter headspace of 33%.|
|SafAle™ T-58 Dry||Fermentis||70||Med||12-25°C (53.6-77°F) ideally 15-20°C (59-68°F)||A specialty ale yeast selected for its estery, somewhat peppery and spicy flavor. Yeast with a good sedimentation: forms no clumps but a powdery haze when re-suspended in the beer.|
|SafAle™ BE-256 Dry||Fermentis||82||High||12-25°C (53.6-77°F) ideally 15-20°C (59-68°F)||Active dry yeast recommended to brew a diversity of beers amongst which abbey style beers known for their high alcohol content. It ferments very fast and reveals subtle and well-balanced aromas. To maintain the aromatic profile at the end of the fermentation, we do recommend to crop the yeast as soon as possible after fermentation.|
|SafAle™ BE-134||Fermentis||90||Low||25-29°C (77-84°F)||This typical yeast strain is recommended for Belgian Saison-style beers and is characterized by a particularly high attenuation. It gives fruity aromas with a spicy character such as clove notes. This strain will produce highly refreshing and drinkable beers. Confirmed by the company to be Saccharomyces cerevisiae var. diastaticus .|
|SafeAle™ WB-06||Fermentis||86||Low||18-24°C (64-75 °F)||This typical yeast strain is recommended for wheat beer fermentations and produces subtle estery and phenol flavor notes (POF+) such as clove notes typical of wheat beers. Confirmed by the company to be Saccharomyces cerevisiae var. diastaticus |
|Lallemand Belle Saison - DRY||Lallemand||High||59-95 ||Belle Saison is also a prodigious sulfur producer, so extended conditioning may be necessary. Verified to be Saccharomyces cerevisiae var. Diastaticus, and killer neutral . Belle Saison yeast is killer neutral, which means that killer wine strains will not kill it . See this MTF thread for more information on this strain. This might be the same strain as WY3711 . Formerly branded as "Danstar".|
|Lallemand Abbaye Belgian Ale Yeast - DRY||Lallemand||Med-High||Low||63-80||Abbaye is an ale yeast of Belgian origin selected for its ability to produce great Belgian style beers including high gravity beers such as Dubbel, Trippel and Quads. The propagation and drying processes have been specifically designed to deliver high quality beer yeast that can be used simply and reliably to help produce ales of the finest quality. Formerly branded as "Danstar".|
- Fermentis 2018 data on re-hydration vs pitching direct for active dry yeast. See also recommendations from Lallemand.
- For information on mixed culture starters, see Mixed Culture Starters.
For long term storage (3 months to potentially 2+ years), slants are a good option. For instructions on how to make slants at home capable of storing any microbe for potentially 2+ years, see Bryan's video on Sui Generis Brewing (requires a pressure cooker).
- MTF thread on freezing yeast for storage, with link to HBT article.
- "Maintaining A Healthy Yeast Bank Long Term", article on HBT.
- Bryan of Sui Generis blog guide to freezing & refrigerating yeast for homebrewers:
Additional Articles on MTF Wiki
- Maltose Falcons Guide To Saisons - Saison yeast profiles
- Coming Clean: A New Method of Washing Yeast with Chlorine Dioxide.
- Esters - Table of esters and their smells.
- The Saccharomyces family, by Lars Garshol.
- VLB Berlin pure yeast cultures.
- Yeast Strain Comparison Chart (White Labs, Wyeast) - information by Kristen England on Mr. Malty website.
- In depth article by Tracy Aquilla on yeast respiration, "How Yeast Use Oxygen".
- A blog article about brewing with Saccharomyces paradoxus by Matt Humbard on A Ph.D. in Beer blog.
- "Here It Is, the Genetic Family Tree of Beer", article on the Verstrepen/White Labs paper on the family tree of yeast.
- YouTube taste comparison of three Yeast Bay Saison cultures, and tips from Drew Beechum on fermenting with saison yeast.
- Wine Strain Chart from Winemakers.com.
- Scott Labs wine yeast inventory, with descriptors of each yeast for thiols, mouthfeel, etc.
- Charlie Bamforth overview of biochemistry of yeast flavors on BeerSmith Podcast; 01/26/2018.
- ref needed
- 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.
- Wikipedia. Saccharomyces pastorianus. Retrieved 02/12/2019.
- 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
- 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.
- Wikipedia. Saccharomyces bayanus. Retrieved 02/12/2019.
- Alternative Saccharomyces interspecies hybrid combinations and their potential for low-temperature wort fermentation. Nikulin J, Krogerus K, Gibson B. 2017. DOI: 10.1002/yea.3246.
- Saccharomyces uvarum, a proper species within Saccharomyces sensu stricto. Andrea Pulvirenti, Huu-Vang Nguyen, Cinzia Caggia, Paolo Giudici, Sandra Rainieri, Carlo Zambonelli. 2000. DOI: https://doi.org/10.1111/j.1574-6968.2000.tb09381.x
- Many interspecific chromosomal introgressions are highly prevalent in Holarctic Saccharomyces uvarum strains found in human-related fermentations. Albertin W, Chernova M, Durrens P, Guichoux E, Sherman DJ, Masneuf-Pomarede I, Marullo P. 2018. DOI: 10.1002/yea.3248.
- "Killer (Zymocidal) Yeasts." Brewing and Distilling Yeasts. Graham G. Stewart. 2018.
- The ecology of killer yeasts: interference competition in natural habitats. Primrose J. Boynton. 2019. DOI: https://doi.org/10.1002/yea.3398.
- Biology of Killer Yeast and Technological Implications. Bijender Kumar Bajaj, Satbir Singh. 2017.
- Yeast viral killer toxins: lethality and self-protection. Manfred J. Schmitt & Frank Breinig. 2006.
- Rima Hatoum, Steve Labrie, and Ismail Fliss. 2012.
- Advances in Microbial Physiology, Volume 22. Academic Press, Sep 15, 1981. Pg 94-95.
- Conversation with Bryan of Sui Generis Blog on MTF on Killer Factor for Saccharomyces. 11/16/2015.
- Strains of Yeast Lethal to Brewery Yeasts. A.P. Maule and P.D. Thomas. 1972.
- A New Wine Saccharomyces cerevisiae Killer Toxin (Klus), Encoded by a Double-Stranded RNA Virus, with Broad Antifungal Activity Is Evolutionarily Related to a Chromosomal Host Gene. Nieves Rodríguez-Cousiño, Matilde Maqueda, Jesús Ambrona, Emiliano Zamora, Rosa Esteban and Manuel Ramírez. 2011
- Antimicrobial Agents Produced by Yeasts. T. Buyuksirit, H. Kuleasan. 2014.
- Non-Saccharomyces killer toxins: Possible biocontrol agents against Brettanomyces in wine? S. Afr. J. Enol. Vitic. vol.36 n.1 Stellenbosch. 2015.
- Production and effect of killer toxin by Saccharomyces cerevisiae and Pichia kluyveri on sensitive yeasts and fungal pathogens. Dabhole, Madhusudan P, Joishy, K N. 2005.
- 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.
- Yeast Interactions in Inoculated Wine Fermentation. Maurizio Ciani, Angela Capece, Francesca Comitini, Laura Canonico, Gabriella Siesto and Patrizia Romano. 2016.
- Antimicrobial properties and death-inducing mechanisms of saccharomycin, a biocide secreted by Saccharomyces cerevisiae. Patrícia Branco, Diana Francisco, Margarida Monteiro, Maria Gabriela Almeida, Jorge Caldeira, Nils Arneborg, Catarina Prista, Helena Albergaria. 2017. DOI: 10.1007/s00253-016-7755-6.
- Biocontrol of Brettanomyces/Dekkera bruxellensis in alcoholic fermentations using saccharomycin-overproducing Saccharomyces cerevisiae strains. Patrícia Branco, Farzana Sabir, Mário Diniz, Luísa Carvalho, Helena Albergaria, Catarina Prista. 2019.
- Saccharomyces cerevisiae variety diastaticus friend or foe? Spoilage potential and brewing ability of different Saccharomyces cerevisiae variety diastaticus yeast isolates by genetic, phenotypic and physiological characterization. Meier-Dörnberg T, Kory OI, Jacob F, Michel M, Hutzler M. 2018. doi: 10.1093/femsyr/foy023.
- 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.
- Kristoffer Krogerus. Milk The Funk Facebook thread post on the significance of STA2 and STA3 genes in diastaticus strains. 06/01/2019.
- STA10: A gene involved in the control of starch utilization by Saccharomyces. Julio Polaina, Melanie Y. Wiggs. 1983.]
- Structural analysis of glucoamylase encoded by the STA1 gene of Saccharomyces cerevisiae (var. diastaticus). Ana Cristina Adam, Lorena Latorre-Garcia, Julio Polaina. 2004.
- Richard Preiss. Milk the Funk thread about STA1 gene correlation to glucoamylase production. 12/31/2017.
- Matthew Peetz of Inland Island and Tobias Fischborn of Lallemand. "Master Brewers Association Podcast" 12/25/2017.
- Richard Preiss. Milk The Funk Facebook group thread on diastaticus strains that do not ferment dextrins. March 2018.
- 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.
- Caroline Whalen Taggart. Milk The Facebook post on how quickly diastaticus ferments. 02/09/2018.
- 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.
- Wade Begrow. "Recent notable microbiological contaminations of craft beer in the United States". Presentation poster at EBC 2017. Retrieved 11/19/2017.
- District Court, Boulder County, Colorado. Case Number 2017CV31132. Filed 11/14/2017.
- Adi Hastings. Milk The Funk Facebook Group post on non-diastaticus strains with high attenuation. 02/27/2018.
- Wade Begrow. "S. cerevisiae var. diasttaicus". MBAA webinar. July 2018.
- Shawn Savuto and linked references. Milk The Funk Facebook book post on POF+ correlation with diastaticus. July 2018.
- Richard Preiss and Justin Amaral. Milk The Funk Facebook thread on plate media for diastaticus. 06/26/2018.
- Richard Preiss. Milk The Funk thread on diastaticus. 11/18/2017.
- Kristoffer Krogerus. Milk The Funk Facebook thread on WLP026. 05/25/2018.
- MTF thread on STA1 gene and White Labs strains that might have it or not. Milk The Funk Facebook group. 12/07/2017.
- Richard Preiss. Milk The Funk Facebook group post on WLP570 and WLP585 being diastaticus. 02/08/2018.
- Saccharomyces boulardii. Wikipedia. Retrieved 12/07/2017.
- Application of Non-Saccharomyces Yeasts Isolated from Kombucha in the Production of Alcohol-Free Beer. Konstantin Bellut, Maximilian Michel, Martin Zarnkow, Mathias Hutzler, Fritz Jacob, David P. De Schutter, Luk Daenen, Kieran M. Lynch, Emanuele Zannini, and Elke K. Arendt. 2018. DOI: https://doi.org/10.3390/fermentation4030066.
- Search on : CBS strain database. CBS. Retreived 04/12/2016.
- <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.
- Terminal acidic shock inhibits sour beer bottle conditioning by Saccharomyces cerevisiae. Cody M. Rogers, Devon Veatch, Adam Covey, Caleb Staton, Matthew L. Bochman. 2016.
- Conversation with Richard Preiss and Tamir Danon on acclimating yeast to sour beer for conditioning on MTF. 03/24/2016.
- "Life’s Secrets Sought in a Snowflake". Emily Singer. Quantum Magazine. 11/03/2015. Retrieved 12/27/2016.
- Evolutionary engineering reveals divergent paths when yeast is adapted to different acidic environments. Eugene Fletcher, Amir Feizi, Markus M.M. Bisschops, Björn M. Hallström, Sakda Khoomrung, Verena Siewers, Jens Nielsen. 2016.
- Origins of multicellular evolvability in snowflake yeast. William C. Ratcliff, Johnathon D. Fankhauser, David W. Rogers, Duncan Greig & Michael Travisano. 2015.
- The Impact of Simple Phenolic Compounds on Beer Aroma and Flavor. Michael Lentz. 2018. doi: 10.3390/fermentation4010020.
- "Recent Advances in Controlling Hoppy Aroma in Beer." Daniel C. Sharp. OSU Brewing Science Presentation.
- Richard Preiss. Milk The Funk Facebook group post on phenols and fermentation temperature. 07/09/2019.
- Distribution of phenolic yeasts and production of phenolic off-flavors in wine fermentation. Shinohara T, et al. J Biosci Bioeng. 2000.
- Eric Bandauski's Yeast Strain Guide
- "Wild Yeast / Brettanomyces / Lactic Bacteria". East Coast Yeast website. Retrieved 04/27/2018.
- Lance Shaner. Milk The Funk Facebook thread on misclassification of Trois and ECY-03b. 12/06/2014.
- May not be Brett as per Lance Shaner on MTF.
- Fermented Homebrew Store website. East Coast Yeast ECY-03B description. Retrieved 05/11/2019.
- Escarpment Labs Yeast website. Strain Collection. Retrieved 02/27/2018.
- Private correspondence with IOY by Dan Pixley.09/04/2015.
- INIS-317 English Ale VII. Inland Island website. Retrieved 02/27/2018.
- INIS-491 Saison: French. Inland Island website. Retrieved 12/07/2017.
- Private correspondence with Justin Amaral by Dan Pixley. 01/24/2018.]
- Conversation with Paul Finney about M29/M27. 03/21/2016.
- Mangrove Jack's Craft Serieis Dried Yeast spec sheet. Retrieved 03/21/2016.
- Robbert Roost private email correspondance with Mangrove Jack customer service; forwarded to Dan Pixley. 12/14/2017.
- Lance Shaner. Milk The Funk Facebook group on OYL-500. 09/18/2017.
- Propagate Lab website. "Yeast Library". Retrieved 11/18/2018.
- SouthYeast Labs Yeast Catalog. Retrieved 3/2/2015.
- The Yeast Bay website. "Policies and Product Information". Retrieved 09/17/2018.
- Conversation with Nick Implellitteri and Ed Coffey on MTF. 08/19/2015.
- Wallonian Farmhouse. The Yeast Bay website. Retrieved 03/20/2018.
- WALLONIAN FARMHOUSE II. The Yeast Bay website. Retrieved 02/06/2017.
- WALLONIAN FARMHOUSE III. The Yeast Bay website. Retrieved 02/06/2017.
- Saison Blend II. The Yeast Bay website. Retrieved 03/20/2018.
- Dry Belgian Ale. The Yeast Bay website. Retrieved 03/20/2018.
- Funktown Pale Ale. The Yeast Bay website. Retrieved 03/20/2018.
- FLANDERS SPECIALTY ALE. The Yeast Bay website. Retrieved 02/06/2017.
- Mr. Malty website. Yeast Strain Sources. Retrieved 01/20/2016.
- 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.
- WLP570. White Labs website. Retrieved 02/28/2018.
- Richard Preiss. Milk The Funk Facebook group post on WLP570 and WLP585 being diastaticus. 02/08/2018.
- White Labs website. "WLP590 French Saison Ale Yeast". Retrieved 02/28/2018.
- Archive of MTF discussions regarding Trois genetic analysis results.
- White Labs 644 Explanation. 04/09/2015. Retrieved 5/2/2015.
- Lance Shaner's results of fermenting Trois with lactose on MTF. 10/12/2015.
- Conversation with Lance Shaner of Omega Labs on MTF. 01/17/2016.
- Richard Preiss. Milk The Funk Facebook post on Trois flavor profile. 02/06/2018.
- Homebrewing Reddit post. 02/26/2016.
- Paul Illa. Milk The Funk Facebook group. 05/01/2017.
- White Labs website. "WLP644 Saccharomyces "Bruxellensis" Trois". Retrieved 02/28/2018.
- Johnny Horn. Milk The Funk post on WLP700 characteristics. 09/07/2017.
- Wild Pitch Yeast catalog. Retrieved 1/2/2018.
- [http://beer.suregork.com/?p=4030 Kristoffer Krogerus. "AN UPDATED BREWING YEAST FAMILY TREE". Suregork Loves Beer blog. 11/16/2018. Retrieved 12/03/2018.]
- Email from Jeannette Kreft-Logsdon. Milk The Funk Facebook post about Wyeast's diastaticus strains. 05/16/2018.
- Kristen England. "Yeast Strain Sources". Mr. Malty website. Retrieved 05/29/2018.
- Dave Janssen. Milk The Funk facebook group thread on WY3711 origins. 05/28/2018.
- Lance Shaner. Milk The Funk Facebook group post on S. boulardii. 09/18/2017.
- Fermentis BE-134 Spec Sheet. Retrieved 02/10/2018.
- Private email correspondence with a Fermentis representative by Jeremy Johns; email forwarded to Dan Pixley for verification. 11/21/2017.
- Fermentis SafeAle™ WB-06 webpage. Retrieved 02/10/2018.
- Marie, Coppet from Lallemand. Private correspondence with Martin Etchart; forwarded to Dan Pixley
- Conversation on MTF with Pierre Hugo Houle regarding Danstar Belle Saison yeast. 01/25/2017.
- Lallemand Brewing website. "BELLE SAISON BELGIAN SAISON-STYLE YEAST". Retrieved 11/20/2017.
- MTF Thread on Belle Saison. 11/20/2017.