If brewmaster Peter Bouckaert seems to have particularly refined palate for beer, it may be because he got a head start on the rest of us. “From 12-18, we always had beer on the table in school,” he says, recalling his childhood in Belgium. “‘Table beer,’ we call it. Beer for kids, with low alcohol—it had like 2.2% or something.”

Long before he was creating some of the most popular beers in the country for New Belgium, the third largest craft brewery in the U.S. (and eighth largest overall), Bouckaert was studying biochemistry at Hogeschool Gent, a renowned university in Belgium’s Flanders region. But he quickly found himself bored and longing for something more. “The guys in the brewing department at university always had hoses and boots,” Bouckaert says. “I liked science, but I got tired of such a small lab scale. The brewing department, those guys were really making something.”

Before long, he’d be making something, too. He got his professional start in the late ’80s at the legendary Belgian brewery, Rodenbach, where he got a crash course in making the sours he’d fallen in love with as a teenager. He’d eventually stumble into founding a brewpub with friends, before finally setting off for Boulder, CO in 1996.

It was there he’d create  boundary-pushing American craft beers like La Folie, a sour brown ale that ages on French Oak barrels from one to three years before bottling. When La Folie was introduced in 1999, most U.S. craft brewers hadn’t touched sours; now, they’re arguably the trendiest style after India Pale Ales. “It’s maybe crazy, but I’ve been involved with sour beers my whole life,” Bouckaert says. He has no plans to stop, either. “I’ve been on a shopping spree the last two years, doubling the wood cellar at New Belgium every years. It’s four times as large as it was two years ago.”

Expect that cellar to keep growing, and for New Belgium to keep making waves. “[My wife and I] were young and just married so it seemed fun to do something else,” he says of his relocation nearly two decades ago. “But I could not have imagined what that company would be. I always said I was going to stay here as long as I can learn, and I’m amazed that I’m still on a sharp learning curve.”

Here, Brouckaert reminisces on the brews that defined his palate and his career, including the sours of his youth and the Sierra Nevada barley wine that convinced him American brewing was ready for a change.