Cassandra Landry | 10.15.2014 | Issue #2


The first sour beer Bob DeMoisey ever had was a Rodenbach Grand Cru, and he loved it immediately. The Flanders Red Ale style beer is a cool 95 on BeerAdvocate, a swoon-worthy 99 on RateBeer.com, and a gold medal winner pretty much anywhere that counts. To a lot of people, it tastes like salad dressing. 

“It’s one of my favorite beers to serve someone who’s never had it before, because you get to watch their reaction,” says DeMoisey, the general manager and curator behind San Francisco’s year-old Mikkeller Bar—a bonafide playground for sour beer fanatics thanks to its extensive list of hard-to-find gueuzes, Flemish red ales, and lambics. He’s been watching the enthusiasm for the dry, tangy styles build from a sly whisper into a full-throated shout for years, first at The Trappist in Oakland, and now behind-the-scenes at Mikkeller.

“Lately, it’s picked up to where, other than IPAs, the biggest question we get is: what sour beers do you have?” he says on a recent weekday. Syrupy, late-afternoon sun is slanting in through the ceiling-high windows of Mikkeller’s Mason Street outpost. It fades into a startling, cool darkness at the bar set against the very back wall, where a few stools are occupied by quiet people contemplating their beers. As soon as the sun goes down, this place will be full to the gills, as it has been almost every night since it’s opening.

Sour and wild beers are a major focus of the draft and bottle list at Mikkeller, taking up three quarters of the bottle offerings and filling an entire “sour room” open to the public on weekends. It’s not entirely intentional—DeMoisey merely follows his instincts and jumps on the chance to order rare beers from around the world that he loves. Many of them just happen to be sours. This means that, much like a freaky city-wide Pavlovian response, if you ask about sour beers in San Francisco, someone near you (drooling slightly) will immediately ask if you’ve been here.

“It’s a different style, which just like anything else makes it feel new, but sour and wild beers have become this huge thing in American brewing,” he continues. “I remember reading about lambic breweries almost going out of business in Belgium because nobody there was buying their beers. Then they started finding a market in the US, and saw that not only could they sell it, they needed to make more.”

Sour beers, a catch-all term that lately seems to include all nature of spontaneously-fermented, barrel-aged, and wild brews, spiked in popularity a few years ago, seemingly overnight. They’re elegant, and niche. Ordering a sour beer with authority feels like you could be the smartest person in the room (“It’s aged in pinot noir barrels, you know”), and they even taste serious, a result of their slow-and-steady-wins-everything aging process. That process has been a bit of risky deterrent to both brewers and buyers in the past: maturation can take years, and the result is a pricy, albeit delicious if you do it right, beer that is rarely available in anything but 375 or 750 ml bottles. Tough sell, once, but goddamn if we aren’t all finally ready to clamber aboard that particular bandwagon.

“People seem to understand all that now,” DeMoisey shrugs. “You’ll pay $15 for a really good glass of wine, and people get that it makes sense to pay the same for a glass of something that’s been barrel-aging for a really long time. You’re not going to get those flavors you’re looking for anywhere else, so it’s worth it.”

Those flavors are thanks in large part to a trio of heavy-hitters that sound like villainous brothers in a Greek tragedy: Brettanomyces, Lactobacillus, and Pediococcus. Brettanomyces, or “brett” for short, is a yeast whose powers of fermentation allow it to gun through almost every kind of sugar, including the kind found in wood barrels. Brett gives most brewers and vintners the heebie-jeebies, partly because it’s volatile, mostly because it’s pervasive. But, if you’ve got the cojones to coax it into submission, you’re rewarded with crazy deep layers of complex flavor that you can’t get any other way.  Lactobacillus and Pediococcus over there are the bacteria working that tartness into your beer that gives it it’s sour moniker. Where the splits between sour, spontaneously-fermented, and wild beers become clear is in the application (or not) of brett and its fellows.

Photo courtesy of Russian River Brewing Company

Photo courtesy of Russian River Brewing Company


Russian River Brewing Company’s “Beautification,” inspired by the Lambic breweries in Belgium, is 100% spontaneously-fermented, meaning that brett (and other wild yeast) is indeed allowed to stretch its legs a bit, but no acidifying bacteria was intentionally added by the brewer. Any flavors and aromas are imparted by exposing the just-brewed beer to an open-air environment—and all the bacteria and microorganisms that go with it— overnight. The beer is then transferred into oak barrels, where it’s allowed to ferment at will and age for a few months. All natural, baby. “Temptation,” on the other hand, a blonde ale aged in Chardonnay barrels with loads of brett, lactobacillus, and pediococcus added in a controlled environment, is a classic sour and is also, crazy good.

Back in 1999, RRBC’s brewer and owner Vinnie Cilurzo decided to take the plunge and experiment with the yeast and bacteria that would eventually make him, by all accounts, the Godfather of American sours. “Temptation” was the result of that initial effort.

“When I started making barrel-aged beers, there was very little information available to brewers on the topic, so for the most part I had to teach myself and learn by mistakes,” he says. “When I started selling these types of beers, we had just one account that would even consider buying them. Now, most good beer bars have at least one barrel-aged or sour on.”

The beers at RRBC are often praised for their finesse and laser-focused intense flavor. It’s not something that comes without learned restraint. “There is a degree of unpredictability with these bugs and critters. They are the ones in control,” Cilurzo explains. “As for flavor, I believe it takes a soft, gentle touch to execute the style. It is easy to go overboard. It is also easy to be far too conservative.”

But for every sub-par sour floating around out there, there’s a bottle that grabs you giddily by the collar with its immediacy and sheer brassiness— beers redolent of Pixie Stix, fresh raspberries, hay fields, that first whiff when you twist a lemon peel, grass, and sun. And it’s not just bar managers like DeMoisey who have noticed the uptick in offerings as they carefully craft their bottle lists: Cilurzo notes that it seems every brewer in the U.S. wants to, or is, making a barrel-aged beer or sour beer. It jives with that whole artisanal, small-batch thing we all love so much. Gypsy brewery Side Project in St. Louis (the brainchild of Perennial Artisan Ale’s Cory King), The Bruery in Orange County, BFM in Switzerland—the list goes on—are all experimenting with flavors and blends that make judges and enthusiasts reevaluate the outer reaches of the sour and wild.

“As this category moves forward, I hope that those new brewers understand how important it is, more than any other style, to put out an exceptional beer,” he says. “If a consumer has a poorly-made pale ale, most likely they will try another. But with barrel-aged or sour beer, if a consumer has a poorly-made version, they may never try the style again because it is so extreme.”

Photo courtesy of Gueuzerie Tilquin

Photo courtesy of Gueuzerie Tilquin


Ten years after Cilurzo, a bio-engineer and statistical geneticist named Pierre Tilquin opened Gueuzerie Tilquin, Wallonia’s (that’s the southern bit of Belgium. Your next Trivia Night team thanks you!) very first gueuze blendery. He deals exclusively in spontaneous fermentation, and only puts out three beers: the classic “Gueuze Tilquin à l’ancienne” (or Oude Tart), a blend of one, two, and three-year old lambics; a spin on the l’ancienne with fresh purple plums dubbed “Quetsche Tilquin à l’ancienne”; and a draft gueuze, a major rarity in the world of bottle-fermented beers and a solid option for sour beer virgins to test the waters before blowing their cash for the night on a full bottle. Tilquin himself is old-school, devoted to maintaining the local tradition and methods of gueuze production, and shares Cilurzo’s hesitations about the flurry of sour beers flooding the market.

“Beers made from a sour mash are, from my point of view, much too basic in taste,” he says. “Sour beers made using a cocktail of different yeasts and bacteria, and undergoing aging in oak barrels... some of them can be very nice, but the major risk in such a process, as for lambic, is the development of an unpleasant acidity. Too much acidity is not a sign of quality, and should be avoided in sour beers.”

The mystery surrounding spontaneous fermentation is what drew Tilquin’s ruthlessly inquisitive mind. “Gueuze depends on many factors that are not yet [fully] understood. It makes gueuze much more fascinating than other beers,” he explains. “[This style] of beer needs time.”

By his count, the interest in Belgium and the rest of Europe is growing, but at a different rate than the fever pitch in American bars. Sour and wild beers are old-hat in that part of the world, and as a result, the palates are usually pickier.

“American breweries are really experimental, and competitive, but in a friendly way. It’s what happened with IPAs, right?” DeMoisey says, back at Mikkeller. “‘I’m going to make a bigger, stronger, hoppier IPA than anyone’ kind of thing.”

That search for the biggest, the loudest, the daring-est, is common for beer hounds discovering something new. They want the extreme, and they’re not shy about it.  

“Lots of people go through that kind of period when they drink beer. I remember wanting the hoppiest, craziest beer I could find, and now I just want some subtlety,” he adds. “It’s the same thing with sour beers. You first get into it and you want to see how extreme it is, but after a while, instead of that intensity you want something that will complement what you’re eating, or be a more relaxing experience.”

For now, we’re enjoying splashing around the envelope-pushing, how-high-can-you-jump side of things. The fervor surrounding all things sour beers will eventually settle into nuanced appreciation, as it always does. Relish the thought that someday, that beer, the one that kind of tastes like salad dressing? The complexities of flavor will be comforting and familiar, that puckering response you have will mellow into languid sipping, and you’ll already be looking for the next challenge.