The brewery at Rodenbach is gorgeous. Its modern, steel-clad system is enclosed in a glass cube that gives brewers a floor-to-ceiling view of the 19th-century brick buildings of the brewery complex. If you ever have a chance to tour Rodenbach, though, you’ll race through it. Unlike most breweries, Rodenbach doesn’t put much emphasis on the practices of the brew house. Instead, when you tour the famous “brewery” in Roeselare, Belgium, the real show happens in the cellars underneath the brewery.
There are 33 cellars in total, and they contain 294 oaken foeders (large barrels), most the size of Ford passenger vans sitting on end. The oldest date back to the 1830s, and they range in size from 120 hectoliters (3,170 gallons) to 320 hectoliters (8,454 gallons). Over the course of the two years beer spends here, it goes through a biochemical transformation to become acidic, dry and fruity—and this, far more than in that modern brewhouse, is where Rodenbach is made.
Rodenbach didn’t always spend a long repose in those cellars, however. Although brown beers have a long history in West Flanders, the inspiration to age them in wood came from points north. The brewery started the practice in the 1870s, after third-generation brewer Eugène Rodenbach returned from England, where he had been making London porter. That beer, the world’s most popular at the time, aged in giant wooden vats and went through a similar transformation as wild yeasts turned rough, acrid beer into something refined and sherrylike. It was Eugène who collected the first of the foeders that would soon multiply like mushrooms in the cellars below and turned the beer into the one we know today.
Rodenbach makes two versions of oak-aged beer, both blends of fresh and aged beer. Standard Rodenbach has 25 percent old stock and 75 percent new beer, while Grand Cru—the masterpiece—is two-thirds aged and just a third fresh beer. The aged beer is amazing stuff. It is extremely dry, reaching 98 percent attenuation in some vats, and drops to a pH lower than lambic’s. (You can sometimes find a product called “Vintage” made of 100 percent 2-year-old beer from a single foeder.)
During the maturation period, esters are created by wild yeasts that are critical to the flavor profile. Rodenbach does not want any funky wild-yeast flavors—the ideal is a clear, sharp note created by lactic and acetic acid—but Brettanomyces is crucial to the final beer because it builds esters so pronounced that some people believe cherries have been added. Grand Cru’s first impression is that clarion acidity, but then the light sweetness from the unaged beer arrives bearing those fruity notes. Somewhere in that alchemy of aging, compounds are created that add the final, unmistakable note to the beer: balsamic vinegar.
Although brewers regularly cite Rodenbach as a favorite brewery and inspiration, the red-brown beers of Flanders are among the hardest to re-create. There are still a few producers in Belgium, but outside the region, good examples are scarce. One of the reasons is that most American brewers don’t realize that beer, not wort, goes into the vats. Until the 1970s, Rodenbach was spontaneously fermented, a process that helped establish healthy colonies of wild yeast and bacteria in the foeders. Those wild microorganisms are extremely potent, so starting with beer rather than wort is critical. “The beer has an alcoholic protection,” master brewer Rudi Ghequire explains, “so it is less risky.” It’s a process called mixed fermentation, and it allows the microbes to create that balance of acids and esters—without funkiness, harshness or the unpleasant byproducts that can come with wild fermentation.
Another reason is the wood itself. The activity in the barrels is fed by the slow ingress of oxygen molecules that come through the oak staves. In very large vessels, there’s less surface area of wood per gallon, so the biology unfolds more slowly. In smaller vessels, everything speeds up. “The reason is very simple,” Ghequire explains. The maturation speed depends on the average of the inner side surface and [volume of beer].” Over time, the brewers realized that the best ratio is achieved in their 180-hectoliter (153-barrel) foeders. American breweries may have a hard time achieving the complexity and balance Rodenbach can because wine barrels or smaller foeders have a higher wood-to-beer ratio.
The final stage is blending. Ghequire and his team start by creating a mother blend of aged beer. Each foeder produces slightly different flavor compounds, so blending them creates the recognizable flavors of Rodenbach. They do this entirely by taste, but then, “we control by gas chromatograph.” Finally, they blend that with the young beer. Ghequire describes the result. “Rodenbach has a triangle of taste: sweetness, dryness and acidity. After two years, you have a very acid beer. And then you blend that acid beer together with young beer to reduce the acidity in your blend.”
The writer Michael Jackson helped popularize the phrase “Burgundies of Belgium” to describe the tart ales of Flanders, and there is something vaguely winelike in this troika of qualities Ghequire describes. But perhaps it’s time to retire that phrase. Rodenbach Grand Cru is simply an incomparable beer. Let’s leave it at that.
Ladyface FlambergeABV: 8.5% | Napa-Cabernet-Barrel-Aged Flemish-Style Red Ale
Tasting Notes: A fairly typical American interpretation, Flamberge leans heavily into the Brettanomyces, with a leathery, horsey nose and a very dry, wild palate. The beer is beautiful, the color of dark honey, and has a layer of cherry esters and delicate spice, but the acetic notes and dusty Brett character suggest an American barrel program much more than the foeders of West Flanders.
Almanac Vanilla Cherry DogpatchABV: 7.5% | Wine-Barrel-Aged Belgian-Style Red Ale w/ Cherries & Vanilla Beans
Tasting Notes: Dogpatch is the name of a San Francisco neighborhood and is useful in announcing this as another American example. Unlike Ladyface, Almanac leans heavily on a very sharp, sour-candy tartness, one made more candylike with the addition of cherry and vanilla. It is a simple, approachable tart ale, but bears few of the hallmarks of oak-aged Belgian versions.
Panil BarriquéeABV: 8% | Cognac-Barrel-Aged Sour Red Ale
Tasting Notes: Of the three, Panil comes closest to capturing the excellence of Rodenbach. Italians are known for making extremely balanced, nuanced beers, and Barriquée is a case in point. It is just lightly acidic, with some residual sugars to balance and Brett in the nose, but not much on the palate. While it lacks the developed ester profile and sharp acidity of Rodenbach, one could still imagine this coming from Flanders.
Jeff Alworth is the author of The Beer Bible.