A FEW YEARS ago, during a visit to De Proef Brouwerij outside of Ghent, Belgium, a group of American beer enthusiasts – a couple of importers, a bar owner and one or two others – sat around a table with famed brewing engineer Dirk Naudts to conduct one of the odder tasting sessions I’ve encountered.
The goal was to design a new brand for the U.S. market, and various ingredients were displayed for sampling. There were hops and some grains, naturally, but what caught everyone’s attention was the dish of grayish-white powder passed furtively from one to the next. Each would pluck a bit from the dish and place it on his tongue, almost as a dare.
Naudts flashed the nasty smile of a man about to pull off a practical joke. Within seconds, our mouths were as dry as bleached leather and our cheeks collapsed into a face-contorting pucker, every last molecule of moisture sucked away.
The powder was pure, utterly sour lactic acid, the granular essence of a unique beer style: Flemish brown ale.
Also know as oud bruin, the variety is marked by a distinct, piquant tartness that is produced by lactobacillus, an aggressive bacterium that infects the ale during fermentation.
Lactic-acid bacterium is a big troublemaker in the brewhouse, turning perfectly good beer into lemons. Occurring naturally and invisible to the naked eye, it was a mystery till Pasteur showed up with his microscope in the 1860s.
Till then, a man (or in the case of the Pendle witches, a woman) could be hanged for causing beer to sour.
But as the brewers of Oudenaarde in Belgium’s East Flanders know well, lactobacillus can be a good thing.
At breweries such as Liefmans and Roman, the bacteria are welcomed into the fermentation tanks, added to the yeast to produce an earthy funk over the months of conditioning. Although this is not spontaneous fermentation, as in the lambic breweries of nearby Payottenland, the effect is much the same. The final flavor is achieved through meticulous blending, with batches of young and aged beer combined to round out the edges, soften the tartness and produce smooth complexity.
(Though made in much the same manner, Flemish red ale, such as Rodenbach, is regarded as a distinct style by some experts because it receives its lactic shock through aging in wooden vats. )
Liefmans Goudenband (Gold Ribbon) is perhaps the benchmark; the late British beer critic Michael Jackson once called it “surely the best brown ale in the world. ” The brewery, established in 1579, filed for bankruptcy a few years ago, but it was salvaged by another Belgian beer producer, Duvel Moortgat. After a couple of years’ absence from the American market, the brand returned last month with a welcome splash.
Its bottles, wrapped in paper, pour a dark ruby-brown, a clue to its rich malt undercarriage. A quaff is lightly sweet and fruity up front with a full body of pilsner, crystal and roasted malt; the finish, though, is acetic and complex with little evidence of hops. Let the bottle sit in your cellar a few months, and the tartness only grows.
It is an acquired taste, it’s true. Novice tonsils, trained on pure lagers, might gag on the sour wonder of lactic acid.
Slowly, though, beer fans are rediscovering the wonders of sour beer. Today, the Great American Beer Festival recognizes no fewer than four separate sour-beer judging categories.
But a round-table tasting of lactic powder? Take my parched word for it: It’ll be a long time till that catches on.
Other oud bruins:
Monk’s Café Flemish Sour, Petrus Oud Bruin, Haandbryggeriet Haandbakk, Deschutes The Dissident, Lost Abbey Red Poppy.
By the way, Liefmans Goudenband is the essential ingredient in one of the classic examples of beer cuisine, Carbonade Flamande. I follow the recipe shared by beer writer Jackson in his 1993 Beer Companion (Running Press):
- 4 shallots
- 2 pounds cubed beef
- Salt and pepper to taste
- 1 teaspoon thyme
- Pinch coriander
- 1 to 2 bottles Liefmans Goudenband
- Mustard to taste
- Chop shallots and fry them in butter in a large pan. Add beef, then add salt, pepper, thyme and a healthy pinch of coriander. Pour enough Goudenband over the meat to cover (2 to 4 cups) and simmer for 1 1/2 hours.
- Remove meat and set aside. Run the sauce through a sieve, return to pan and thicken with flour, adding mustard to taste. Simmer and stir for 2 minutes.
- Return the meat to the gravy, heat. Serve with boiled potatoes and a glass of Flemish brown ale.