Brasserie de la Senne and the Making of a Brussels Beer
Yvan De Baets is reserved and scholarly. I have exchanged emails with him for years, and these qualities are evident even in his prose. They’re more obvious when you meet him in person, particularly if you do so in his brewery, as I did a few weeks back on my trot through Belgium.
De Baets speaks in complete, grammatically-precise sentences. Point to any object in his brewery and ask a question, and De Baets will offer a meticulous response indicating the level of consideration that goes into each detail. But for De Baets, a piece of equipment isn’t just an important tool, it’s part of a continuum in the tradition of Belgian brewing that extends back centuries. Even more importantly—the tradition of Brussels, which by the new century had dwindled to just a single brewery.
Situated in Time
Yvan De Baets.
“The first brewery of Brussels dates to 979, and quickly the second one came after that,” he told me as we stood in front of his brew deck. “We were proud, when we brewed the first batch here in 2010, that we at once doubled the number of Brussels breweries, as Cantillon was the only remaining local brewery at the time.” Most breweries are aware of their regional status and positioning. With De Baets, there’s another dimension—time. Brussels exists not just in space but time, and Brasserie de la Senne was always a project of a city with a thousand years of brewing history.
De Baets founded the brewery that would become Brasserie de la Senne with fellow brewer Bernard Leboucq in 2003, but it wasn’t located within Brussels until 2010. By then, de la Senne’s twin flagships, Taras Boulba and Zinnebir, had become house favorites in town, and helped spark a mini-revival of brewing in Brussels. Hop-forward and bitter—by Belgian standards—they seemed to signal a new move in the direction the rest of the world was heading. Soon Duvel would introduce “Tripel Hop,” a nod to the American trend in dry-hopping, and many others would follow. Yet if you imagine this was a young brewery following international trends, you mistake Senne’s purpose.
The idea that Belgian beer isn’t hoppy is true only if you consider the breweries making beer now. De Baets rejects the idea that it is anything but purely Belgian. “Of course. Americans always think they invented hops and dry hopping,” he said with a chuckle. “I am collecting brewing books and I have a huge library and in most of the ancient Belgian records you have traces of dry-hopping.” He agreed that the practice was no longer a current feature of Belgian brewing—“most of the other breweries, they have forgotten it”—but this is an example of the way De Baets, who teaches a course on brewing history at the local brewing university, thinks of de la Senne’s place in Belgian brewing. The terrain doesn’t just stretch from Liège to Bruges, but from the present back into the distant past.
Getting the Gist
Over the course of a tour, it also emerged that hops aren’t actually the most important element in de la Senne’s range of ales. Like most other Belgian breweries, yeast—“gist” in Flemish—is. As we entered the fermentation room, De Baets became animated in a way he didn’t when talking about mash regimes or even the hop growers he knows in Germany and Slovenia. “My yeast is the most important living being in the brewery; she is more important than me,” he said. “She is a ‘she.’ I know in your language, she should be an it. She’s a she; I love her. She is my best friend.”
Belgian beer is defined by yeast, which is treated differently than it is anywhere else. In his brewery, De Baets personally designed the fermenters to create a nurturing and happy environment. What was the best way to achieve that? Again, he turned to the past. “The answer I found in old tanks from the 1930s. When I started my career, I had the chance to work in a brewery [that] used cylindrical, flat, open fermenters, and I loved the flavor profile of the beer coming out of those tanks.” This led him to consider the way beer is commonly made, in tall, slender fermenters. But that, he knew, put a lot of stress on the yeast. The benefit to the brewery is efficiency. “Instead of asking how much beer can I put in this room, the question was how will I make my yeast happy?” he asked, and then remembered those old tanks. “I started to think about it, to talk with old brewers, and the answer was: go wide.”
The stress from tall fermenters comes from the weight of the liquid pressing down, and that in turn causes the yeast to release chemical compounds in the wrong amounts. The more pressure placed on yeast, he said, the more higher alcohols will be produced. Lower pressure puts those alcohols in balance with the amount of fruity-tasting esters the yeast will produce. “This ratio between the two is the key to balance. Hence to drinkability.”
It is common for newer craft breweries to use multiple strains of yeast. They can achieve a more “typical” profile for a beer if they tailor the yeast to suit each style. Brasserie de la Senne uses only one strain for its ales. This has even led to criticism of a predictable profile across the breweries beers—but to De Baets, that’s a feature more than a bug. Until recently, every brewery used a single strain by default. They repitched the yeast from one batch to the next, so every brewery inevitably created a “house character” that defined each brewery. That suits De Baets. “I want that very yeast to sign all the beers we make,” he said. Moreover, working with one strain allowed him to really get to know her. “It takes one brewer almost a life to get to know your yeast. I have one life; I cannot have 20 different yeasts.”
Like nearly every other Belgian ale brewery, Brasserie de la Senne finishes the beer with refermentation in the bottle or keg. (This has even inspired the brewery to do small batches of English-style cask ale, which follows a similar protocol.) This gives the yeast a final opportunity to flavor the beer. This is such an important moment of punctuation for the beer’s development that it even matters whether the beer is stored standing up or laying on its side. “If you fill a bottle and referment it standing or lying, it’s totally different,” he explained. “It’s mellower when lying and drier when standing.” Senne prefers to leave them standing in a room of 23˚C/73˚F.
There is a subtle irony to the brewery’s focus on yeast. This is one way de la Senne is more modern than traditional. It is now perfectly characteristic of the Belgian approach, but that wasn’t always the case. In the 19th century, the treatment of the malt was far more important. Breweries conducted elaborate methods to mash the malt and boiled the wort for incredible lengths to produce concentrated, presumably dense beers. In old accounts, yeast is barely mentioned. The focus on yeast only became possible once Belgians gained some control over it. They were able to store and use pure strains of Saccharomyces. The process of re-pitching them thousands of times caused them to evolve into the brewery-specific strains we now know. De Baets was able to source de la Senne’s yeast from another brewery he admired. No doubt the character will eventually change so that the flavor of the yeast from the two breweries will no longer taste the same.
Since the brewery launched their beers in the early aughts, tap handles pouring Taras Boulba and Zinnebir have multiplied throughout Brussels, making them twin hometown beers. Of the two, Taras Boulba is the most expressive example of the brewery’s style. Hugely effervescent, it crackles like club soda and builds up a thick head of meringue, roiling with a tempest of bubbles. It has a wholly unique flavor: a bright lemon up front—that’s the yeast—stiffened by minerality and then a slow evolution toward a dry, herbal finish, something closer to cocktail bitters than typical hops. It is somehow both unexpected and perfectly Belgian. Perhaps, given another decade or two, we might even say perfectly Brusselian. Surely that’s a context in which De Baets already sees his brewery.