Although Saccharomyces cerevisiae was so named for beer because it was first identified at a brewery, yeast strains from the species have been fermenting juice into wine for nearly as long. Brewing inevitably became more industrialized and scientific than winemaking because beer ingredients could be transported and stored for centralized production before refrigeration. Even with the explosion of craft breweries, today there are still 2,000 more wineries in America, yet these wineries produce only 1⁄7 the volume (27,514,101 bbls of wine1 compared to 189,839,914 bbls of beer2 in 2016). If winemaking had been the more industrialized beverage we might be pitching Saccharomyces vinum into our wort.
The (often inaccurate) winemaker stereotype is a refined person in a crisp shirt strolling through their rustic vineyard in contrast to the tattooed brewer in a grungy urban factory. However, when it comes to the yeast in their employ, it is wine yeast that is less genteel. Most strains of beer yeast have been living in breweries year-round for centuries, leaving the yeast pampered without need to compete with wild strains. On the other hand, commercial wine strains continued to overwinter in the vineyards until relatively recently, causing many wine strains to retain their ability to kill competing yeast.
Wine strains are selected for different reasons and adapted to different conditions than beer yeast. Their resulting unique characteristics can be beneficial for brewing in the right context. The most common use of wine yeast in beer is for bottle conditioning, where their high alcohol and acid tolerance allow it to easily carbonate a barleywine or Flemish red. Wine yeasts were selected to enhance the fruit flavors of the grapes and so can free, alter, or reinforce the same compounds contributed by hops or fruit. However, wine yeasts’ subsistence on the glucose and fructose in juice result in most ill-equipped to ferment the complex starch-derived carbohydrates in wort. While there is potential for beer fermented by wine yeast, there are many considerations before pitching them into wort.
Similar to brewer’s strains, wine yeasts ferment sugar into ethanol and carbon dioxide. However, their long-term diet of simple sugars means that most wine strains didn’t develop as many copies of the genes responsible for transporting and splitting maltose and maltotriose.3 As a result, almost all wine strains struggle to surpass 50% apparent attenuation in a standard wort. One reported exception is Lalvin ICV K1-V1116. Low attenuation is an obvious hindrance but also can be turned into an advantage in certain situations, like sour beers. It is clear that wine strains are usually not ideal choices to pitch into an under-attenuated imperial stout!
There are a few options to mitigate the attenuation issue. The first is to produce a highly-fermentable wort. This approach could include an extended mash held at a temperature favoring beta-amylase (145 °F/63 °C) potentially augmented with simple sugars in place of 10-20% of the malt. The same goal can be accomplished with the addition of commercial enzymes; amylase powder or Beano® can even be added to the fermenter.
Another approach is to use a standard wort and pitch a blend of wine and brewer’s yeast, or stagger them allowing the beer strain to finish what the wine yeast started. This process isn’t as simple as it is for teaming-up two brewer’s yeasts, as I wrote about a few years ago (“Collaborative Fermentations” – BYO March/April 2015). With wine yeast there is an additional factor to consider. Many wine yeasts produce a “kill factor” protein capable of incapacitating susceptible yeast, including almost all beer strains. There are different versions (e.g., K1, K28), and while they attack cells in a variety of ways the end result is much the same. Rather than being considered a detriment, many winemakers prefer killer strains because they defend the wine from other unwanted wild Saccharomyces present in the must.
Most yeast labs list whether or not a strain is a killer or not,4 so consider a sensitive or neutral strain (e.g., Lalvin 71B) for co-fermentation with brewer’s yeast. If that isn’t an option, pitch less than 2.5% killer yeast and the sensitive strains will be unaffected.5 The same study also notes that the peak activity of the kill factors is between 4.2 and 4.7 pH, which is the usual final pH of beer.
Wine strains benefit from the same sorts of conditions in terms of aeration, nutrients, and pitching rate as beer yeast. Their ideal temperature has a similar range to brewer’s yeast with white wine strains thriving as cool as lager yeast (as low as 50 °F/10 °C) and red wine strains as warm as saison yeast (as high as 95 °F/35 °C). In Farmhouse Ales (Brewer’s Publications, 2004), Phil Markowski even theorizes that the Saison Dupont yeast may have mutated from a red wine strain given the similar temperature requirements. Consult the yeast lab’s recommended temperature range for the strain as a starting point.
Between 81-95% of wine yeasts produce phenolic aromatics,6 similar to Belgian, hefeweizen, and many wild Saccharomyces strains. These can range from clove to smoky to rubbery. Wort contains more of the precursors including ferulic acid (1-7 mg/L7) than grapes (<1 mg/L8), especially when wheat malt is added or a low-temperature ferulic acid rest is used. The lack of ferulic acid in grape juice is one reason that we usually don’t taste high-levels of pepper or clove in wine.
Interactions with Hops
Many sophisticated drinkers compare the character of Nelson Sauvin hops to New Zealand Sauvignon Blanc wine, but this isn’t just beer-judge banter; both contain 3-sulfanyl-4-methylpentan-1-ol (3S4MP) and 3-sulfanyl-4-methylpentyl acetate (3S4MPA) which provide some of their shared citrusy aromatics.9 3S4MP is also found in high concentration in Mosaic® and Hallertau Blanc hop varieties.10 There are compounds that other hops and grapes have in common as well. In addition, some “varietal enhancing” wine yeasts are fantastic for freeing bound hop aromatics from water-soluble glycosides (“The Science of Hop Glycosides” – BYO July/August 2015). As a result, wine yeast may have a modifying or enhancing effect on hoppy beers!
Much of the interaction happens during the yeast’s growth phase, so the hops added to the boil are essential. You might choose specific varieties and additions to accentuate a particular contribution. For example, I hopped an IPA with Simcoe® late in the boil because the concentration of the thiol 3-mercaptohexan-1-ol (3MH), reminiscent of grapefruit and passion fruit, increases with up to 20 minutes at a boil (while catty 4MMP decreases).11 Certain wine yeasts have the ability to convert 3MH to 3MHA (similar tropical and citrus flavors but with a sensory threshold at 4 ng/L compared to 60).12 In addition to a standard pitch of brewer’s yeast for 5 gallons (19 L), I pitched 1 g of Anchor Alchemy II, a yeast blend developed by Anchor Wine Yeast with that specific conversion in mind for South African wines. The passion fruit aromatics didn’t jump out compared to the half of the batch without wine yeast, but the wine yeast did create a brighter more saturated citrusy hop flavor.
Sour Beer Primary Fermentation
One consideration for mixed-fermentation sour beers is leaving enough carbohydrates (often in the form of dextrins) for the bacteria (especially Pediococcus) to create lactic acid. Often this result is accomplished with a hot mash temperature, creating wort that is unsuitable for a clean brewer’s yeast fermentation. Wine yeast, being less attenuative, can be used for primary fermentation before or in conjunction with Brettanomyces, Lactobacillus, and Pediococcus. Luckily, none of these are sensitive to kill factors and the Brett will change the phenols created. I have found sour beers primary fermented with wine yeast (including Lalvin BM45) to retain some of their interesting aromatics. Consider a strain that produces high-levels of glycerol (e.g., Lalvin S6U) to enhance mouthfeel.
Like hops, fruits other than grapes can provide compounds for wine yeast interaction. The enzymes used by the yeast have an optimum pH higher than a typical finished sour beer though. Usually I wait to add fruit until a couple months before bottling; to give my trial the best chance to succeed I had to change tacks. I brewed a Flemish red with dried sour cherries (1 lb. in 5 gallons/0.45 kg in 19 L) added after a Danstar 58W3 (Viti Levure) primary fermentation. The dried fruit provided a pervasive cherry-backdrop, enhanced by the wine yeast. After souring on the dried fruit for six months I transferred the beer onto homegrown sour cherries and local dark cherries for a final burst of fresh fruit aroma (Recipe found here). The combination was magical, one of the best sour beers I’ve brewed!
There are a multitude of wine strains available, but not a lot of documented experience when it comes to fermenting beer with them or analysis of their interactions with hops and non-grape fruit. Like most experiments, the easiest way to begin is to divert a small percentage of wort to reduce the risk and allow for comparison. See what strains work with which ingredients, and share your experiences with the rest of us! Wine yeast are often inexpensive, so you are only risking a couple dollars with the payoff being unique flavors, better mouthfeel, and a signature character that may be surprisingly wonderful!
1 Statistical Report – Wine https://www.ttb.gov/statistics/2016/final16wine.pdf
2 Number of Brewers by Production Size – CY 2016 https://www.ttb.gov/statistics/production_size/2016_brew_prod_size_ttb_gov.pdf
3 Distinct Domestication Trajectories in Top Fermenting Beer Yeasts and Wine Yeasts http://www.cell.com/current-biology/pdf/S0960-9822(16)30984-8.pdf
4 Lallemand Wine Yeast Strain Quick Reference Chart https://www.math.fsu.edu/~gmizell/mead/Lallemand%20Yeast%20Quick%20Reference.pdf
5 Killer Factor in Wine Yeasts and its Effect on Fermentationhttp://www.sawislibrary.co.za/dbtextimages/tredouxhg.pdf
6 Distribution of Phenolic Yeasts and Production of Phenolic Off-Flavors In Wine Fermentation https://www.sciencedirect.com/science/article/pii/S1389172300800407
7 Control of Ferulic Acid And 4-Vinyl Guaiacol In Brewing http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1996.tb00918.x/pdf
8 Sugars, Organic Acids, And Phenolic Compounds of AncientGrape Cultivars (Vitis Vinifera L.) From Igdir Province ofEastern Turkey https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4362841/
9 Identification and Characteristics Of New Volatile Thiols Derived From the Hop (Humulus Luplus L.) Cultivar Nelson Sauvin (Dagger) https://www.ncbi.nlm.nih.gov/pubmed/19243103
10 Development Of A New Quantitation Method For Polyfunctional Thiols And Its Application For Investigation Of The Characteristic Aroma of “Flavor Hops” https://www.asbcnet.org/events/archives/2016/proceedings/Pages/135.aspx
11 Behaviors of 3-Mercaptohexan-1-ol and 3-Mercaptohexyl Acetate During Brewing Processes https://www.asbcnet.org/publications/journal/vol/abstracts/ASBCJ-2008-0702-01.htm
12 Anchor Alchemy Yeast Blends https://www.oenobrands.com/files/PDF/Anchor/Alchemy/Anchor-Alchemy-Yeast-Bends-Product-Data-Sheet-EN.pdf