Breakout Brewery: Bokkereyder

“New lambic blender” are words not often spoken, but upstart Raf Souvereyns’s Bokkereyder lambic brand is putting that phrase in headlines with a distinct nod to the blending tradition and a progressive attitude toward incorporating winemaking techniques.

Jamie Bogner Dec 10, 2018 - 13 min read

Breakout Brewery: Bokkereyder Primary Image

Photo by Jamie Bogner

“Absolutely not.” Raf Souvereyns does not want photos taken in his industrial warehouse in Hasselt, about an hour outside of Brussels. He’s a private person, and publishing photos of what is basically his second home seems like sacrilege. We meet on a summer Sunday during the Belgian cherry harvest, and Souvereyns, along with a handful of friend volunteers, are packing cherries into barrels then racking beer on top of them. We taste some cherries, destined for his kriek, and they’re sweet but rich with layers of earth and almond. They’re not the well-known Schaerbeekse variety, but a flavorful variety from a farm south of Brussels that Souvereyns prefers. He doesn’t choose fruit or methods based on lambic tradition or consumer familiarity but is on a mission to bring the fruit-handling techniques of winemaking into the world of spontaneously fermented beer.

“When I started this whole thing, I knew why I wanted to do it—I knew it could be done in a different way, from my experience at wineries learning about winemaking,” Souvereyens says. “I don’t want to sound pretentious, but I knew that I could possibly make something better or at least give it a very different twist. Whether it’s better is very subjective, but I could make it a whole different product.” Bokkereyder, the brand (named for the creatures of Dutch folklore that rode on the backs of goats provided by Satan), started inauspiciously—as a home-blending project in his grandmother’s house. A winemaker sent him home with a small barrel and suggested he age some lambic in it. After acquiring some inoculated wort from De Troch, he aged that beer for a year, added some cherries to the barrel to make a kriek, and the result was…disappointing.

“It was the worst beer I’ve ever made,” says Souvereyns.

But the experience only encouraged him to experiment with new methods, to make the beer he envisioned in his head. He acquired more barrels and more inoculated wort and honed his fruit techniques. Eventually, the personal project grew into a bona fide business.


“After more than two years of making beer, I found that there are people who actually drink it and even pay for it, and that was the best part. I was doing it as a hobby basically and found out that people like this stuff. That’s how the whole thing started to develop into a business—by coincidence. I never forced anything. That’s counterproductive for a thing like this anyway.”

As we talk, Souvereyns is direct, self-deprecating, and honest almost to a fault. “I don’t know much about brewing beer,” says Souvereyns. “But when you start with something, it’s better to know why you’re doing it, and along the way you’ll figure out how to do it and what exactly you’re going to do.”

Lambic blending is a time-honored tradition in Belgium, and it’s common for blenders to not brew their own wort. For many years, Drie Fonteinen existed as a blender but not brewer. Tilquin, similarly, purchases wort from breweries to blend and create their own beers. Bokkereyder sources wort from three different lambic breweries—Girardin, Lindemans, and De Troch. The wort is loaded from those breweries’ coolships into a portable tank that Souvereyns picks up the day after it’s brewed, drives back to his warehouse, and racks into barrels.

“Those who brew beer for me have done it for generations and have all the expertise—the coolships, the right environments, and the microflora in their brewery. I love working with them, and I trust their knowledge and experience,” he says. “Maybe at some point I might brew my own beer but right now, no.”


The inoculated wort from these brewers each has its own distinct personality, and Souvereyns makes decisions along the way that impact how each of them develop. Girardin brings a touch more bitterness than the others but features low acidity and more body. De Troch is light-bodied with subtle citrus notes. Lindemans has a consistent and specific lactic-acid profile. Each wine barrel he chooses further develops those characters in distinct ways, and all of these are things Souvereyns considers as he constructs blends.

“I ferment those three in my own barrels, and the result turns out to be a very different beer from any of the three. They’re all three very, very different. With those three, I can make a million different blends. But also it’s nice that they’re so different because in every fruit beer and even every gueuze I make, every blend is different—the ratios of beer from different breweries and different ages. “One important thing [when blending] is acidity,” says Souvereyns. “Calling lambic ‘sour’ beer is not exactly right, I think. It’s just one part of what lambic is, although a very important part.”

Our conversation turns to the subject of fruit, and Souvereyns opens a bottle of Pjassel, a lambic macerated on red peaches that provide a much richer red-orange color than is typical of beers made from the fruit. The acidity is surprisingly restrained, and the peach flavor carries through with notable definition and clarity. Next, we try Wijngaard Muscat & Riesling, a blend made with wine grapes that exhibits a hearty, earthy depth rarely found in beers made with white-grape varietals. Wijngaard translates to “vineyard,” and this line of different beers all showcase different white-wine grapes and techniques.

“This is made with the principle of orange wines,” says Souvereyns. “The plan was to make it with Riesling and White Muscat, but the Muscat was not that good that year, so I took Blue Muscat instead. And that’s why it doesn’t look like an orange beer or orange wine anymore—it’s red.”


“The way I’m making it is similar to orange wine—a long maceration of both Riesling and Muscat. So you have not just the fruity part of the grape but also the floral, slightly herbal, but phenolic thing out of it. I really like that combination from them. I think it makes a much more complex beer with those grapes. After maceration, this one was aged for more than a year in barrels.”

Most brewers add fruit to beer at the end of the brewing process, in stainless-steel tanks or in barrels for a few weeks or a few months before packaging. Souvereyns prefers to leave the beer on fruit for much longer times—as long as six months to a year for his grape beers—then racks the beer off the fruit and back into barrels to mature further.

“[My] grape lambics are aged in oak for sometimes two years after fruiting. It brings the whole thing together and makes it much more complex. Even the cheapest wines you buy in the supermarket are aged in stainless-steel for a half year before they bottle. Why do they do that for a wine that costs 3–4 euros? It must be absolutely necessary in order to have an okay wine; otherwise, it’s too costly to go through that process. I think the same about the fruit lambics I make.”

Other fruits demand different techniques, as the more delicate stone-fruit flavors are susceptible to degradation if not handled carefully. His apricot and peach macerations are long, relative to others in the industry, at six months. But he insists on steel tanks for those.


“The micro-oxidation you get in barrels will kill those beers,” says Souvereyns. “They’re very sensitive to oxidation. Except for the vineyard peach—that one can stay in barrels for an extended time, and it actually needs micro-oxygenation. Every fruit is different, so it’s hard to say, but I think the whole thing has to come together either in a barrel or a steel tank. It needs some time before it goes in the bottle.” It’s not that the methods other brewers use are wrong—bottling right after maceration—but he finds that results come quicker when the conditioning happens in barrels or tanks.

“The same process that happens in the barrel also happens in the bottle. If you bottle it right after maceration, it will happen in the bottle as well, but it’s much slower. It takes years in bottles, and if you do it in a barrel instead where it picks up that oxygen, it adds to the complexity,” says Souvereyns.

That same focus on conditioning in barrels extends to his gueuze blends. “The way I make gueuze is very different from how other people do it. I always make my gueuze in a barrel, so I blend one-, two-, and sometimes three- and four-year-old lambic in specific wine barrels and let that age. Those are finished lambics from somewhat neutral barrels. I always let them ferment together in a barrel before I bottle them.”

As we drink and talk lambic, we’re surrounded by oak wine barrels. Our table is a barrel on its side. They’re stacked five high in three rows from the front to the back of the warehouse. But the barrels themselves aren’t just inexpensive fermentation and aging vessels. Souvereyns considers them to be an additional ingredient in his beer as well as a factor that ultimately limits his yearly production.


“I know the full history of every barrel you see in here. My beer spends so much time in a barrel that it’s basically an ingredient. So there’s a limit to how many barrels I can get with a full history and how many people I know in the wine industry.”

Souvereyns loves to ferment his beers in freshly dumped wine barrels (ones where there should not be any latent spontaneous culture in the barrel itself). He works only with wineries that clean and prep their barrels to his standards, and he’ll give them a rinse when they arrive but doesn’t do anything that would destroy any of the wine character of the barrel. He’s counting on the spontaneous inoculation to do the fermentation heavy lifting and has noticed an interesting phenomenon with these “new” second-use barrels.

“The funniest thing about the old cultures and stuff is that in general, a ‘virgin’ barrel that has come directly from a winery, versus an old lambic barrel—if you put the same batch of wort in them, the virgin barrel will get to a lower gravity than the previously used barrel, even though the used barrel should contain more of the yeast that’s inside lambic. That’s an interesting thing, I think. It actually nullifies the whole argument about cultures in barrels. It’s contrary to what many people believe. I don’t have any opinion about it, but I observe. And I can say in 80 percent of the cases, the lambic will reach a lower gravity in the virgin barrel.”

The bottles continue to flow, and eventually we realize that, despite the sun still shining, it’s 10 p.m.—a reminder of Belgium’s high latitude. Souvereyns presses a bucket or two of leftover cherries into juice using a wine press, for a friend to make jelly, and stashes it in a cooler. Today’s harvest is processed, and there will be more tomorrow. It’s high-fruit season, and fruit gets processed and used as quickly as it’s picked. Stone fruits will be harvested soon, requiring more urgent labor. The cycle continues.

Souvereyns is philosophical about how interest in his beers has grown and how his techniques have improved over the past five years. In lambic years, five is nothing—brand new—and he still has much to explore and refine.

“The homework you have to do to create something new takes a lot of time. Trial and error,” he says. “There’s no final answer to this. It keeps it interesting for all of us.”

Jamie Bogner is the Cofounder and Editorial Director of Craft Beer & Brewing Magazine®. Email him at [email protected].