Brett loves the wood

Green Flash opened the doors to its Cellar 3 barrel-aging facility in Poway on May 16, giving the public a glimpse of the sort of wild-yeast experimentation barrelmaster Pat Korn has been developing over the past two and a half years. For the grand opening, 15 of the tasting room's 24 taps were assigned to brett beers, sours, and other barrel-aged efforts.

Strictly speaking, the 12,000-square-foot space is not a brewery. That work is still done at Green Flash's Mira Mesa home base, where brewmaster Chuck Silva continues to craft Green Flash releases made primarily using strains of Saccharomyces, better known as brewer's yeasts. However, portions of those beers — or at least the pre-fermented wort — are diverted to Poway via truck, and pumped into massive wood foeder (pronounced fooder) barrels to ferment with Brettanomyces, or brett, the wild-yeast strain most commonly associated with Belgian-style ales.

"The whole idea of having the foeder is that you're getting consistent mass inoculation for the 25–30 barrels you're going to fill out of it," says Korn. "It's trying to be consistent with something that's called wild."

The word "consistent" comes up a lot when Korn discusses the challenges of wild yeasts, which are a big reason brewing requires obsessive cleanliness to succeed, particularly when wood barrels are involved.

"The brett loves the wood," Korn points out. "It stays in the wood forever — it's almost impossible to get rid of."

That's a driving factor in Green Flash opening this secondary facility — to reduce the risk of contaminating their regular roster of beers. The internationally distributed brewer has also expanded its barrel program from about 40 barrels to 550 and counting, thus deepening their pursuit of sour ales. "We were just doing brett beers [in Mira Mesa], because sours were just a whole other headache that you had to deal with," Korn says.

In the quest for consistency, he worked with local yeast purveyor White Labs to isolate a signature brett strain used in all of his barreling efforts, which he describes as having a "very lemony, verbena, pineapple flavor." He's dedicated one foeder entirely to sours, another to Flanders style ales, and two to funk beers. Once a beer has spent a week or more fermenting in a foeder, it's transferred to smaller, 225-gallon barrels where secondary fermentation begins, sometimes with lactic-acid-producing bacteria Lactobacillus or Pediococcus, often with fruit purée added to feed them.

Of the 15 Cellar 3 beers available at the grand opening, most were variations of individual beers, each having received different barrel treatment. For example, for Natura Morta, a 100% brett-fermented saison aged in wine barrels, three varieties were on tap: blueberry, strawberry, or cranberry. A fourth aged with plum will be bottled in coming weeks. And while a first release of bourbon-aged Silva Stout spent time in Heaven Hill barrels, a future release is aging in barrels that once contained Woodford Reserve.

Inspired by similar large-scale barreling efforts by Firestone Walker and New Belgium, Cellar 3 marks the largest barrel program undertaken thus far in San Diego, a bet that San Diego's beer tastes are evolving as consumers' palates become more sophisticated. In doing so, Green Flash CEO Mike Hinkley has given Korn the freedom to experiment and occasionally fail, all in pursuit of "something different."