A broad American craft category for sour ales intentionally acidified via kettle souring, mixed-culture fermentation, or barrel aging with Lactobacillus, Pediococcus, and/or Brettanomyces. Ranges from light and refreshingly tart (quick kettle sours) to deeply complex and funky (long-aged mixed-culture beers). ABV varies widely, 4–8% typical; tartness and complexity are the defining traits, not a specific gravity or color.
In the glass
Origin
American sour ale grew out of a generation of craft brewers who took their cues from the classically tart beers of Belgium — lambic, Flanders red, and oud bruin — rather than treating acidity as a flaw. An early anchor was New Belgium’s La Folie, a wood-aged sour brown built by Peter Bouckaert, who had come to the Fort Collins brewery from Belgium’s Rodenbach; the culture living in its foeders is among the longest continuously maintained in American brewing. On the West Coast, Vinnie Cilurzo began barrel-aging beers such as Temptation during his time at Russian River, which became its own company in 2003. In Michigan, Ron Jeffries founded Jolly Pumpkin in 2004 as what is generally regarded as the country’s first all-sour, wood-aged brewery. Brewers then pushed past imitation toward distinctly American interpretations, aging beer in wine, bourbon, and whiskey barrels and blending across casks much as gueuze blenders do. A handful went further still and attempted true spontaneous fermentation: in 2007, Allagash installed a coolship in Maine and brewed what is generally credited as the first traditional spontaneously fermented beer made on American soil, eventually blending it into Coolship Resurgam. Alongside these long-aged approaches, brewers also developed much faster kettle-souring methods, giving the category a range that runs from quick, clean-tart session beers to multi-year barrel-aged blends.
Notes
This is a broad, catch-all category rather than a tightly defined style, and how a given beer was soured matters more than its color or strength. A kettle sour, soured quickly with Lactobacillus before a normal boil and fermentation, tends to be clean, bright, and one-dimensionally tart; a barrel- or foeder-aged mixed-culture beer built with Lactobacillus, Pediococcus, and Brettanomyces over months or years develops deep funk, oak, and complexity closer to its Belgian models. Two related labels travel with these beers: “wild” generally describes Brettanomyces-driven, earthy character, while “sour” describes bacterial acidity, and many beers are both. Because individual barrels mature differently, blending is central to the craft.
Defining examples
Russian River Temptation·Jolly Pumpkin Bam Bière·Allagash Coolship Resurgam·Jester King SPON·Cascade Kriek