When I interviewed Stillwater brewmaster Brian Strumke last week, we talked mostly about philosophy, food, and his reinvention of the saison style. Not once did he indicate that, given the time and space, he could produce sour beers that would rival Belgium’s most rarefied beers.
The beer was Red 33, a bracingly sour prototype he poured at Monday’s Stillwater beer dinner at Birch & Barley. Red 33 is what you might call a “lab lambic.” Instead of using ordinary brewer’s yeast, Strumke feeds it doses of wild yeast and bacteria that, in Belgium’s traditional lambics, spontaneously inoculate the beer, flying in through open windows and landing in the uncovered koelschip. Unlike brewer’s yeast, these wild critters produce large amounts of lactic and acetic acid during fermentation. That’s how most sour beers are made — but that’s not the coolest part.
For Red 33, Strumke brewed three similar batches (same basic recipe, slightly different yeast strains) in three years and blended them into the final product in the fourth year. He added a small amount of cherry puree at this stage, mostly to feed the yeast some more sugar and reawaken them for a final fermentation. This blend of 1-, 2-, and 3-year-old beer mimics Belgian gueuze, which similarly is a blend of aged lambics. The difference — and this is the coolest part — is that Strumke aged his lab lambic in in glass carboys, not the traditional wine barrels. This results in some obvious differences, such as less oak flavor and thus less astringency. But it also reduces the burning effect that extremely acidic food can leave in your throat and belly.
Much of sour beer’s acetic acid (which is in vinegar) comes from a bacteria called acetobacter, and acetobacter is aerobic, i.e. it feeds on oxygen to produce acetic acid. In porous wine barrels, the beer is constantly touching air, so the bacteria can breathe the oxygen it wants. In glass, no air flow means less oxygen, which means less acetic acid. Thus, no belly burn.
At the hands of a talented brewer — by definition, a bit of a chemistry geek — little practices like this elevate an experimental beer to a refined, world-class product. Red 33 drinks with the intense tartness of sour cherries and a dry, puckery finish that sets your mouth watering. Because it’s aged in nonreactive glass rather than oak, the three-year blend sports the bright freshness that I’ve only tasted before when visiting lambic breweries in Belgium, where they greet you with a glass drawn straight from the barrel.
“It’s better living through chemistry, man,” Strumke said. “The knowledge is out there. Just because we don’t traditionally make [sour beer in the U.S.], it doesn’t mean we can’t.”
For now, Strumke is keeping his sole batch of Red 33 for special events, and he doesn’t know when he’ll make it again. Three years of aging requires more time and space than most breweries can afford to sacrifice. But Strumke says everyone he does business with wants him to rejuvenate his lab lambics, and he’s begun looking for a space for the project.
“A lot has happened in the last six months that I didn’t expect. Who knows what’ll happen in the next six years.”