The alternative approach for brewing sours is to go old-school and just let all the wild yeast and bacteria in the air drop into the beer naturally. It's risky but — when done right — can produce magnificent beer.
That's the strategy Ron Jeffries at Jolly Pumpkin in Dexter, Mich., uses. He's a pioneer of the sour movement in America, and he made some of the first commercial sours way back in 2004.
"There's wild yeast and bacteria everywhere, especially if there are orchards nearby," Jeffries tells The Salt. "When you make a happy home for them in your barrels, they just show up and spontaneously ferment — and sour — a beer."
"For thousands of years, all beer had sour notes to it," Jeffries says. "It was refreshing and crisp because people didn't understand how to keep things clean.
"Then with pasteurization, refrigeration and an understanding of how to keep cultures free of bacteria, beers started to become nonsour," he says.
A handful of breweries in Belgium continued to produce sour beers, known as lambics, Flanders ales and guezes. But it's craft breweries in America that are making them fashionable again.
"They're taking the beer style in crazy directions, just like they did with IPAs and porters," Jeffries says. "The reason why you're seeing sour beers gaining popularity is because they taste great, but also because of the creativity of American brewers."