Brewers, winemakers and cidermakers are continually on the hunt for the ideal flavor profiles for their fermented beverages. And the key to manipulating those flavors is yeast.
“With beer, you’re taking this kind of gross, bitter soup of sweet barley and hops, and the yeast makes it taste good. Depending on the yeast that gets put in it, it can make it taste like 400 different things, so there’s so much potential there. I think that’s really exciting,” says Richard Preiss of Escarpment Laboratories. Priess was joined by Doug Checknita from Blind Enthusiasm Brewing and Patrick Rue from Erosion Wine Co. to discuss the world of yeast in TFA webinar, A Yeast Primer.
“If you’re invested in vegetable fermentation, yeast might be sort of clouded in mystery and something that is unwanted,” says Matt Hately, TFA advisory board member who moderated the webinar. “It’s what you live by in beverage fermentation in wine and beer and it’s the key to unlocking flavors to make that magic happen.”
Domesticated vs. Wild Yeasts
Just as dogs and cats were domesticated by humans, yeasts have been as well, says Priess, whose company makes and banks yeasts. They are microscopic organisms that adapt, “so if someone’s making beer for over the span of hundreds or thousands of years then the yeast is going to change to kind of get better at fermenting that beer and maybe it’s not going to be so good at surviving out in the wild, just like our toy poodle versus our wolf.”
Other fermented drinks, like wine, sake and cider, use different yeasts with their own specific sets of traits. This is why a wine yeast can’t be used in a beer and vice versa, “though there are some opportunities to experiment.”
Fermenting with wild yeasts has become increasingly in vogue with beer brewers. Aspirational brewers are finding yeasts on the skin of fruit or the bark of trees.
The panelists on the webinar praise experimentation, but note there is risk. Priess says yeasts designed to survive in the wild can be challenging to use in a beer. Checknita points out the safety factor in using yeasts directly from nature as well, “you can get stuff that’s harmful to human health so you have to be careful with your pH levels and what controls there are.”
Traditional winemakers, on the other hand, have long used the wild yeast on grapes to ferment. Rue notes that 10 years ago winemakers began to deviate from this tradition to use pure cultures instead. This process is how many large-scale, industrial producers operate today. But smaller winemakers, who often want to emphasize the specific traits of their terroir, generally use native yeasts and traditional winemaking techniques.
“It’s amazing how wine is how God intended wine to be made because you let nature happen and you’ll probably have a pretty good result with natural fermentation,” Rue continues, “where beer, it’s very touch-and-go, you have to have the perfect conditions and I’ve been able to do spontaneous fermentation with those yeasts.”
The Yeast Family Tree
There’s a large and continually-growing family tree of yeasts, with branches forming for genetic diversity and specialization.
Priess sees three new trends emerging in yeasts: traditional yeasts (like Norwegian kveik) being rediscovered, yeast hybridization (similar to cross-breeding a tomato) and genetic engineering to enhance certain traits of yeast.
“That’s the exciting part of what we’re doing is no one really knows the best approaches to using beer yeast yet, but there’s a lot more new science that’s happening, a lot more brewers that are experimenting, and together we’re collaborating to understand how to work with yeast better and kind of unlock new flavors and new possibilities,” Priess says.
Checknita agrees. He says new yeasts are forming new family trees through spontaneous fermentation, which is taking the base of a beer and experimenting to “push and change those yeasts to do what we want and get that clean flavor that’ll make a beer that tastes good to the human palate.”