Of Barrels and Brettanomyces
Swing Tree Tames the Yeast That Must Not Be Named
Brettanomyces. It’s a kind of yeast, not a made-up word. And beer and wine producers fear this fabled yeast as much as wizards fear Voldemort.
“Some winemakers and brewers who find the dreaded yeast strain Brettanomyces will literally burn their barrels,” says Brandon Overstreet from Swing Tree Brewing Company “It’s super gnarly, and will keep on living when all other yeasts would not, they just don’t want to risk it spreading.”
So why has Overstreet decided to bring in six used wine barrels infected with Brettanomyces, or Brett, into his brewery?
“When used with care it can impart this wonderfully rich aroma and flavor of earthiness and leather,” he says. “It’s literally the perfect yeast for the brew that I’m creating.”
There was a time when all beer was brewed, transported and aged in wood. With access to metal brewing equipment and advanced sanitation techniques, brewers today can make much more consistent, controlled and affordable products. Brandon, alongside many of the best and most successful breweries in the country are taking beer back to its roots with barrel aging, a tag you’ve probably noticed on some of the more specialty-labels in the beer aisle. The space and time needed for this process—as well as the upfront expenses and high-risk of spoilage—makes for a necessarily expensive product. But if you can look beyond the price tag, these dynamic and exciting brews challenge what we think beer should taste like.
Swing Tree’s first barrel-aged beer, a sour called the Hungry Tongue, is currently aging in six Petit Syrah barrels that will impart “a unique fruitiness to the beer” according to Overstreet.
“I got the barrels from a local winery because this yeast is really bad for wine and spreads like none other,” he says. “However it’s perfect for this sour because Brett lives longer, eats more sugar and will result in a drier, earthier final product.”
Wood barrels or casks that are used for aging beer can be obtained from a large variety of sources. They are almost always made of French or American Oak which imparts its own set of nuances. The commonly associated flavors are vanilla, toast, cocoa, baking spices and coconut. Casks are porous and the “temperature fluctuations in the brewery cause the liquid to get sucked in and out of the wood, letting in a little bit of oxygen which feeds other bacteria and yeast that enhance the flavor of the beer” says Brandon.
Microbreweries across the country employ a huge variety of used barrels in their aging processes including old whiskey, tequila, rum and sherry casks. Each imparts their own notes (some more pleasant than others). A used wine barrel will impart flavors from its particular variety whether it be Chardonnay, Pinot Noir, etc., and they often age best with a sour. Whereas a used Bourbon barrel imparts deep and intense flavors that generally age well with big robust brews like stouts and porters.
Caldera, another Ashland brewery, uses bourbon barrels for their Mogli, a Oak-Aged Chocolate Imperial Porter.
“You taste the beer with a serious whiskey kick that tickles the tongue and imparts some spicy wood notes,” says Ray Cato, Caldera brewer. “The whiskey really makes this chocolate beer taste amazing.”
They source their bourbon barrels from Kentucky and Tennessee, aging the beer for around six months. Ray says that “the whiskey barrels bring an intense flavor to the beer that can only be duplicated by barrel aging the beer.”
For a brewer to achieve their desired flavor profile it takes care, diligence and a good dose of luck because each individual cask has its own distinct character. Some barrels will age beers dryer, others more acidic, some with heavier woodiness and others will have a stronger profile of whatever booze used to be in it. Blending is often associated with big brewers making predictable and bland product that always tastes the same. Most beer connoisseurs consider it about as acceptable as dropping the F-bomb in church. However, with barrel aged blending is not only a necessity, but a difficult art form. Next month, when it comes time to bottle, Brandon will blend all six of his barrels to achieve the desired complexity and balance with a big malt flavor and notes of raisin, fig and plum with complimenting fruit undertones.
At the conclusion of our interview, he pulled a little bit of the Hungry Tongue out of a barrel and we toasted to exciting new beers. After over a year in the barrel the flavors are already well formed and promise a complex and exciting sour. The last few months of its aging will be done in the bottle.
Personally, I’ll be waiting outside the Swing Tree for its winter release.