Sour beers are said to be the oldest style of beer in the world. For thousands of years, according to craft brewer and sour beer enthusiast Trevor Klimek of Paw Paw Brewing Company (Paw Paw, Michigan), all beers were sour beers, fermented by wild yeasts in the air.
Wild yeasts, along with bacteria—and, in some cases, fruit (think cherries or raspberries)—give sour beers a pronounced acidic flavor. Sour beers are typically dry, made with little or no hops and are often more reminiscent of wine or cider than other beers.
Long popular in Belgium where they have historically been made with spontaneously occurring yeasts and bacteria, sour beers are increasingly trendy among craft beer lovers in the United States who enjoy their refreshing, funky flavors.
The Last Frontier
Klimek calls sour beers “the last frontier of American craft brewing.” Craft brewers, he points out, have embraced everything from extreme malted beers to high-alcohol imperial stouts to super hoppy brews: “They have jammed in as many hops as you can in a fermenter!” Sour beers, however, are a new challenge.
Indeed, several Michiana brewers told us that they do not brew sour beers because they are “too risky.” Wild yeast, Klimek explains, is more aggressive than conventional ale yeasts, and if brewers don’t work extra hard to keep everything perfectly clean, wild yeasts can cross contaminate other beers—and nobody wants wild yeasts in their mild English ale.
But, Klimek is emphatic, brewing with wild yeast is totally doable for small-scale brewers. “One of my huge passions,” he says, “is to introduce sour beers to people”— including fellow brewers.
If brewers can maintain separate Belgian and American yeast strains in their operations, Klimek says, they can contain sour yeasts as well. Paw Paw Brewing Company, along with The Livery Microbrewery in Benton Harbor, Michigan, which has been brewing sours for almost a decade, are cases in point.
Local Cultures With A Cult Following
In 2008, Klimek began propagating the wild yeasts that he now uses at Paw Paw Brewing Company at his home in Paw Paw. When he approached Paw Paw’s owners about making sour beers shortly after they opened in 2011, they were initially skeptical. Now, he says, the brewery’s sour beers, which include four flagship sours: Bluegrass Sour Blonde, Barrel Aged Sour James, Red Barn Sour and Free Range Sour Stout (all aged in oak barrels from St. Julian Winery in Paw Paw) as well as “extra special really crazy fun things” like a Sour Spruce Ale—a sour stout made with spruce tips—have developed a “cult following.”
The Livery’s sours also have serious fans. Verchuosity, a barrel-aged Belgian amber ale made with sweet and tart Michigan cherries, has an overall score of 99 points on RateBeer.com and is rated as the #11 fruit beer in the world. Other popular sour styles at The Livery include a bière de garde aged in white wine barrels from Tabor Hill Winery (Buchanan, Michigan), a Belgian golden quadruple aged in bourbon barrels and a kriek made with Michigan cherries.
Paw Paw Brewing and The Livery both typically have at least one sour on tap.
Something In The Air
Today, a handful of other local breweries are also producing sours. Iechyd Da Brewing Company in Elkhart, Indiana, uses a sour mash to make their TataRosa, a raspberry Berliner weisse— a sour wheat beer traditional to Northern Germany. Owner Summer Lewis explains the process as one of “funkifying” the mash (the mix of heated water and grain) by allowing it to sit out overnight. During that time, the acidity rises and the mash begins to ferment. The result is a mildly sour beer with a gorgeous pink color from the added fruit. (TataRosa is only available seasonally in the summer months.)
Round Barn Brewery in Baroda, Michigan has made several sours in the past two to three years. Brewmaster Chris Noel is currently working on culturing local yeast strains to develop a sour style specific to Southwest Michigan in collaboration with Greenbush Brewing Company in Sawyer.
At Round Barn, the brewery’s first batch of sour beer was a happy accident from their early days when the brewery shared a building with the Round Barn Winery. (They are now in separate locations.) One day, the machine used to squeeze grapes for the winery ended up in close proximity to the beer fermenters. “All of the sudden,” says Chris Noel, “the room started smelling like grapes.” When they tasted the beer a few days later, it was deliciously tangy. The name of that first batch? Mother Pucker.
With its abundance of raspberries, grapes and other fruits, Southwest Michigan’s fruit belt, Trevor Klimek says, “is a fantastic place to have wild yeast in the air”—and a perfect place to make sour beers