Your sour beer under microscope, courtesy of bevshots

Shortly after rescuing the Anchor Brewery in 1965, Fritz Maytag threw a party to spread the word. A veritable who’s-who of San Franciscans, including the mayor, RSVP’ed. But instead of celebrating, the fete nearly turned into a funeral. “We had in those days,” said Maytag, “two tanks of beer and we filled about one hundred kegs per tank. And it was all sour.” The beer, it turns out, was grossly infected with sour-taste-making bacteria, to the point where Maytag jokingly referred to it as a “Belgian beer.” The story has a happy ending—employees fortunately tracked down enough refrigerated kegs to slow the bacteria’s growth, and folks were none the wiser—but that’s where Anchor’s strict adherence to thorough sanitation originated. So while each of Anchor’s early products pioneered their American craft iterations from IPA to porter to barleywine, the brewery is now one of the few craft breweries in the nation not championing, or even dabbling, in this thing called ‘sour beer.’

A one-man Lewis and Clark of the American sour frontier is Vinnie Cilurzo, owner and brewmaster at Russian River Brewing Co., just a short hop north from Anchor. He’s the guy responsible for a series of Belgian-influenced sour ales including Consecration, Supplication, and others that start with Brettanomyces (yeast that plays a big part in sour beers) and end with “–ation.” In penning the entry for ‘sour beer’ in the Oxford Companion to Beer (OCB), Cilurzo reiterates Maytag’s knock that, “When speaking of beer, the word ‘sour’ is usually a pejorative.” He adds, “That said, there is a range of older beer styles that are traditionally acidic, and together with modern variants inspired by them, they have been termed, perhaps a bit rakishly, ‘sour beer.’”

A great many beers fall under that category, from Flemish Reds and Oud Bruins to Lambics and an entire host of ‘wild’ ales, so termed for employing rapscallion yeasts and bacteria that can take an infected beer down a thrilling journey way off the beaten path. Make no mistake about it; when a beer ferments spontaneously via wild yeast, it is indeed infected. For this reason, makers of sour beers tend to view themselves less as brewmasters, for that implies being the master of the brews, and more as wranglers or curators guiding the end result via blending, patience, and a little prayer.

Going to extremes

Whether a beer is intentionally inoculated with yeasts such as Brettanomyces, or simply allowed to become host to these untamed critters through the allure of wort (beer’s unfermented origins) cooling beneath the night sky where ambient yeast and bacteria hitchhike on the breeze, the result offers flavors found at the extreme fringes of what is often called beer’s flavor wheel. Seriously, go to Beerflavorwheel.com to learn more. And if there’s one thing beer connoisseurs dig above all else, it’s extreme flavor. Join said fanatics at Puckerfest held at Belmont Station in Portland and Sour Fest thrown at the Stone Brewery near San Diego. Each festival is celebrating its sixth anniversary this July.

When you think about it, the history of craft beer has always been about pushing the boundaries of flavor and taste. Thirty years ago, the revolution began by shifting from pale lagers to pale ales like Sierra Nevada’s. From there, we’ve rapidly evolved to Russian River’s Pliny the Elder being a benchmark for double IPA, pale ale’s cousin on ‘roids. It stands to reason that Russian River’s Sonambic ales are the standard bearer for American craft sour beers. Sonambic, by the way, is what Cilurzo dubs his spontaneously fermented beers. Lambics are the provenance of Belgium’s Senne Valley, where breweries produce authentic, spontaneously fermented sour beers. Because the native bacteria adrift in Sonoma are different than those floating around Brussels, Russian River Brewing Co. refrains from purloining Lambic’s classification. Two things Lambic producers and Russian River Brewing Co. have in common are profoundly acidic beers and devoted fans. It’s those fans, perhaps more than the makers of the beers, who are propelling the popularity of such ales.

Sour passion kids

The practice of inoculating beer with earthy, funky Brettanomyces and sour-producing microflora such as Lactobacillus and Pediococcus is infecting the brewing industry. “What is certain, if improbable, is that sour beers are taking hold, especially in the United States,” writes Cilurzo in the OCB.

New Belgium Brewing

in Colorado lured brewmaster Peter Bouckaert from the Rodenbach brewery in Belgium, before beer geeks vociferously started clamoring for more sour beer, resulting in their heralded beer, La Folie. In Portland, Oregon, the Cascade Barrel House is a domestic mecca for sour beers, earning both gold and silver medals in the wood- and barrel-aged sour beer category at the 2009 Great American Beer Fest for their Bourbonic Plague and Vlad the Imp Aler beers, respectively.

But the category’s popularity permeates the beer culture beyond the American West, and delicious offerings emanate from New York’s Captain Lawrence Brewing and Massachusetts’ New England Brewing, to the somewhat surprising locales of Nebraska and Indiana, where the Omaha Brewing Co. and Upland Brewing Co, respectively, keep less metropolitan regions awash in sour.

While statistics aren’t available for how many craft breweries create sour beers, more and more are experimenting with the style, meaning you’re likely to find at least a few barrels of the stuff stashed away somewhere in the brewhouse. Moreover, a significant handful of the new breweries in the planning phase—numbering over 700 altogether, according the Brewers Association—aim to offer sour beers predominantly, if not exclusively. Examples include The Rare Barrel in Northern California and the Ale Apothecary in Central Oregon.

If you delve into this acidic world, sip gingerly. Just as you’d probably have a hard time devouring a whole lemon, palate-obliterating sour fatigue is a real thing.

by Brian Yaeger