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Beer

The Yeast Hunters

August 24, 2021

Story: Laurel Miller

photo: Dingding Hu

Beer

The Yeast Hunters

August 24, 2021

Story: Laurel Miller

photo: Dingding Hu

Meet the couple supplying some of the country’s most lauded brewers with a taste of native Texas terroir.

“‘Wild’ means different things to different people,” says Mara Young, co-founder of San Antonio’s Community Cultures Yeast Lab. “Many brewers use it as a synonym for ambient or spontaneously fermented beer or a mixed culture, but it can also be a negative term referring to bacterial contamination.” If Young and her husband, microbiologist Rob Green, have their way, “native” will instead become the newest word on craft brewers’ lips, but they’re not chancing ambiguity.

The couple started their company in 2016—the only yeast lab in the southern United States to provide a full range of commercial brewing yeast strains, custom propagation, wine yeast and mixed cultures—and soon established a niche discovering what Young calls “microregional native Texas yeasts sourced directly from nature.”

To clarify, all yeasts are regional and sourced from the environment. “To make a Belgian beer you need Belgian yeast, even if it’s cultivated in America,” explains Young. But Young and Green felt there was also a market for domestic beer styles developed entirely within the United States—yeast included. After starting their lab, they set out to discover yeast strains unique to Texas. “We really wanted to find something new and special that captured the terroir of the state,” says Young.

The couple, both avid outdoor recreationalists, collect yeast samples by swabbing native plants, fruit and cacti when they’re backpacking or kayaking using proprietary shelf-stable collection kits that do not require picking the plants. In the lab, “The yeast is cleaned up, isolated from any bacteria and then grown as a single pure culture,” explains Young. “If it’s a brewer’s yeast, we test it by fermenting it in small beer experiments. This allows us to taste and document its flavor.” Those specimens that exhibit desirable flavor profiles are then propagated and sold.

Currently, the Community Cultures catalog features 10 different “expressions” from two Saccharomyces subspecies—S. cerevisiae (the predominant strain of brewer’s yeast) and S. pastorianus—that have been sourced from microregions of Big Bend, the Hill Country and the Gulf Coast. These previously unknown indigenous yeasts yield terroir-centric characteristics, like “a hint of juicy tartness and end notes of apricot, clove and baking spice” in an expression swabbed from wild yellow columbine from Cattail Falls in Big Bend National Park, or “vanilla liqueur, spiced banana, orange” collected from a bloom in the Chihuahuan Desert.

By cultivating these strains sourced from all over the state, our research has evolved to represent the terroir possible in Texas yeast.

One of the couple’s earliest collaborators was Dripping Springs’ Jester King Brewery, the first Texas brewery to make spontaneously fermented beer its primary focus. Co-founder Jeffrey Stuffings saw the creative possibilities in using new indigenous yeasts from a different part of Texas. “In my experience, native strains have the potential to produce flavors and aromas that are otherwise unobtainable,” he says.

For Jester King’s 2020 Desert Series, Stuffings and his team created two dry-hopped oat saisons, fermented with yeast from prickly pear and salvia plants, respectively, collected from two different microregions of Big Bend. “The flavors were beautiful—the prickly pear had cool apple/pear and sauvignon grape flavor and texture, while the salvia displayed overripe fruit with a mellow earthiness,” says Stuffings. “So much of the beer world, especially on a macro level, is focused on uniformity and consistency. Native catalogs help create richness and diversity in beer, which I think makes it more fun and enjoyable.”

The resulting beers are singular—an amalgamation of the yeast profile, grain, hops and other ingredients, as well as brewing and beer style. “The flower or whatever plant the yeast comes from is simply part of its story,” says Young. “By cultivating these strains sourced from all over the state, our research has evolved to represent the terroir possible in Texas yeast.”

Though Community Cultures has found a Texas following with low-intervention winemakers, kombucha brewers and bakers, craft breweries are their primary accounts. “Today, brewers are all about playing around with ingredients and flavor profiles. With wine, it’s largely about terroir and varietal, but around 70 percent of flavor in beer is due to the yeast,” says Young.

Devotees of their native catalog also cite simple pragmatism. “Winemaking is a slower process with a once-a-year harvest,” says Karen Killough, co-founder and apiarist at Driftwood’s Vista Brewing. “The availability of grain and different yeast strains allows brewers to be more experimental, with lower risk.”

Vista is one of a growing number of breweries seeking custom native yeast strains from Community Cultures. Some, like Houston’s Eureka Heights Brewery, have requested yeast with geographical proximity to their facilities. For Eureka, Green swabbed a pink star flower penta at the Houston Museum of Natural Science’s Cockrell Butterfly Center, which yielded a strain with delicate stone fruit aromas and flavors and hints of pepper and clove. (The resulting beer is still a work in progress, says co-founder and head brewer Casey Motes.)

There’s just something magical about capturing a moment of time and place in a beer.

Pollinators played an even more active role in the development of Vista Brewing’s Hive Mind Honey Ale. “[Rob and Mara] were taking samples at our brewery in Driftwood for a spon [spontaneously fermented beer] project, when a honeybee from our hives flew into the production area,” says Killough. “We were able to swab the bee without harming her, and it turned out she was carrying S. cerevisiae.”

The resulting test batch, which drank like a light Belgian beer, was so good that Killough and her husband, Vista co-founder Kent Killough, created Hive Mind Honey Ale, a “true collaboration brew” that uses honey of various varietals, donated by 25 Central Texas beekeepers, alongside the yeast collected from the errant bee.

To make custom yeast strains like these more accessible, Community Cultures now provides collection kits to some of their accounts. (They also sell to select homebrew suppliers.) For herbalist and brewer Trevor Nearburg, founder of Beerburg Brewing in Dripping Springs, the kits have helped his brewery come full circle.

“We use as many local ingredients as possible, including grain,” Nearburg says. “My approach to terroir is very literal, and [head brewer] Gino Guerrero and I forage for all of the botanicals in our seasonal Wildcraft Series.” Some of these plants, like mugwort, horehound and bee balm, are used in place of hops. What Nearburg can’t find on the brewery’s 15 acres he sources from his family’s ranch in Brownwood; Community Cultures’ yeast collection kits have enabled him to take swabs from both properties to create beers like his Horehound Golden Ale, a bright, assertively bitter Belgian style made with a prickly pear–derived S. cerevisiae strain called “The Windows,” after the Big Bend hiking trail where it was collected.

“Having yeast sourced from the same herbs, flowers and fruit we use for brewing is very important to me,” says Nearburg. Plus, adds Young, “There’s also an emotional and psychological reaction people experience when drinking something with such a strong sense of place—there’s just something magical about capturing a moment of time and place in a beer.”

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