Last weekend Boom Island Brewing released the second beer in its Spontaneous Series — beers that are funky, tart, and wild, and brewed using traditional Belgian techniques. “Spontaneous” is a reference to historical brewing methods in which batches of sweet wort were allowed to ferment naturally, based on the microorganisms in the environment or primitively introduced to the liquid (on a stick or branch, for example). The latest from the Minneapolis brewer, Triple Brett, is named for the three strains of Brettanomyces that were employed in its fermentation.
Unlike average brewer’s yeast, Brettanomyces (often called Brett) was first isolated in something undesirable — infected wine. Vintners and brewers went to great lengths to prevent this naturally occurring yeast from entering their unfermented product, a very sugary, hospitable environment. But in a transformation similar to that of penicillin, the microbe has been tamed and put to work for the greater good.
Well, almost tamed. Brett is known for being unpredictable, even though it is becoming fairy common on brewery menus nationwide. With a flavor profile that contains descriptors like “barnyard” and “over-ripe fruit,” plus flavor compounds chemically similar to those of feet and cheese, the stuff is risky to use on a number of levels, not just for the beer but for the entire brewery. Brett, as well as other specialty microorganisms, can run rampant, entering batches inadvertently, so cleanliness and control are key.
Triple Brett is even more unusual in that it is fermented entirely with the wild yeast, with no standard-issue brewer’s yeast at all. The strains that brewer Kevin Welch (above) chose for this beer were intended to deliver on aroma as well as taste.
Triple Brett has an earthy and sweet aroma, with notes of straw and caramelized berry as well as an undeniable barnyard fragrance. Much of what it is in the glass does not reveal itself until the beer has warmed a bit. Sip by sip, layers of both sweet and funk come together and present like an over-ripe cherry, yet the finish remains dry with an occasional lingering Malt-O-Meal note in the back of the throat.
Unusual yeast is not the only reason for the depth of flavor. The fermented beer was aged for 10 weeks in French oak red-wine barrels, adding a dark stone-fruit component.
Unlike sour beers, which also rely on microorganisms for their tart flavor, Triple Brett is classified as a Wild Ale, similar to the Brett Mikkels Ale from Surly. The berry and stone-fruit notes are like those in Bemidji Brewing’s Flanders Red, a traditional take on the Belgian sour style.
Triple Brett is available in 750 milliliter bottles for $12 at the Boom Island tap room and at varying prices at liquor stores.