Stumble into any brewery, and you’ll likely see a few 53-gallon barrels. They probably once held whiskey; now, they probably hold the latest batch of wood-aged porter or stout.

But they’re small potatoes compared to the three oak behemoths at Right Proper Brewing Company’s Brookland production house and tasting room. The wooden tanks, known in brewers’ parlance as “foeders,” once fermented wine at Stone Tower Winery in Leesburg. They can hold about 65 whiskey barrels’ worth of beer.

The Right Proper team believes those behemoths also hold the next big trend in craft beer, akin to the explosion in farmhouse saisons and gose in recent years. Only this time, says co-owner Thor Cheston, “It’s bigger than a certain style. It’s a different approach to the brewing process.”

“I think we were ahead of the curve,” he adds. “People may have thought we were ludicrous in bringing in three 45-hectoliter French wine casks when we opened. Now, they think we’re only slightly ludicrous.”

To be fair, foeders aren’t exactly novel technology. Locally, you’ll find one at 3 Stars Brewing Company; in Colorado, New Belgium has scored dozens, and Flemish breweries like Rodenbach have been using them for centuries.

But for Right Proper brewmaster Nathan Zeender, that’s precisely the point. He’s infatuated with brewing’s pre-scientific (and pre–stainless steel) days, when he says the craft was shrouded in “magic and shamanism.”

If there’s any alchemy going on, it’s in how the oak interacts with Right Proper’s house culture—a blend of farmhouse yeast strains, brettanomyces yeast, and lactobacillus bacteria that drives the flavor of many of its beers. The “brett,” in particular, finds its way into the wood, and continually influences the beer as it matures in the foeder for weeks.

Unlike stainless tanks, foeders aren’t sterilized between batches, adding to their uniqueness. The wood is “a living, breathing environment for our house culture,” which changes a little bit every time it’s re-pitched for a new batch, says Zeender.

Among these batches is Ornithology, an ancient, wine-like style of wheat beer called a grisette; White Bicycles, a rustic witbier brewed with black limes; Astral Weeks, a dry-hopped saison; and Baron Corvo, a high-alcohol, malty biere de garde, which lives in the brewery’s only foeder that once held red wine (the rest held white).

“These beers have our real imprint on them,” says Zeender. “That’s something I’m really proud of.”

Click here for more stories from the 2016 Beer Issue.