Belgium has long been regarded as being home to the world’s greatest spontaneously fermented beer:
lambic. Fermented with wild yeasts and bacteria falling from musty wooden rafters, blowing in from hay fields, or floating in from the Zenne River, lambic is inextricably tied to the geography of Belgium, so much so that the term “lambic” can only be applied to beers made there.
As American brewers seek to make more diverse styles, many are venturing to produce lambic-like beers fermented with microorganisms native to their respective locations. But just like sparkling wine made outside of Champagne, France, can’t be labeled as Champagne, American brewers also can’t technically consider their beers as lambic or gueuze. This has created a conundrum for breweries: How to promote a beer known as one thing without using the term that best identifies it? Enter Méthode Traditionnelle.
A term created by a group of American brewers excited about making lambic-style beers, Méthode Traditionnelle is still catching on as a designation. Eventually, the group that created it hopes consumers will recognize the label as an extension of the lambic beer making tradition, yet one whose varieties are distinct from its Belgian forebearers. It’s a lofty goal, considering many drinkers aren’t even aware of what a Belgian lambic or gueuze is, but Méthode Traditionelle is slowly starting to take root.
What Makes Lambic Special?
Traditional lambic beer production is both primeval, drawing a throughline from the earliest spontaneously fermented beers, and exceptionally sophisticated. Over the centuries, brewers have perfected the intricate and delicate process, which requires advanced technical brewing skills and just-right environmental conditions. Following an involved mashing process that breaks down complex starches into fermentable sugars and a lengthy boil that concentrates the wort and uses aged, oxidized hops to add preservative qualities without the typical aroma or bitterness contributed by fresh hops, the unfermented wort is transferred to an open, typically shallow vessel called a coolship for the most important part of the process—overnight cooling and inoculation.
During the cooling phase, the wort becomes inoculated with wild yeast and microflora, which impart an array of complex flavors to the beer, making each batch a little different than the next. Overnight temperatures below 50°F are needed to properly cool and dose the wort with the right mix of microbes, restricting the traditional lambic brewing season to fall and spring months.
Once the wort is cool, it’s transferred to barrels and wooden casks to be exposed to more wild bacteria, and then left to ferment for up to three years, or until it has achieved the brewery’s desired flavor profiles.
Lambic by Another Name
Many U.S. breweries make spontaneously fermented beer using similar processes to those used in Belgium. In Minnesota, Boom Island Brewing makes several lambic-style beers, including kriek, a sour beer made with cherries, and Oude Funk, a gueuze-like beer. (Gueuze is made by blending spontaneously fermented beer that is one, two, and three years old.) Boom Island founder and head brewer Kevin Welch was inspired to make his own versions of gueuze and kriek while visiting Belgium over the course of several years. The first place he visited, in 2007, was Brasserie Cantillon, one of the best-known lambic breweries in the world. It was love at first sip.
Over multiple trips, Welch got to know Cantillon’s owner and learn more about lambics. “[I] also gained a respect for the fact that it was a really beautiful tradition,” Welch says. “You can duplicate and do your best to do wild fermentation on our own terroir, on our own ambient atmospheric wild microbes.”
To bridge the gap between brewers’ respect for Belgium’s lambic breweries and their own desire to brew spontaneously fermented beers, a collection of U.S. breweries formed the Méthode Traditionnelle Society. Helmed by brewers from places like Jester King in Austin, Texas, Black Project in Denver, Colorado, and Funk Factory in Madison, Wisconsin, their goal is to better market their lambic-inspired beers to consumers.
For a beer to qualify as Méthode Traditionnelle, it has to meet several requirements established by the group’s board and three-person steering committee. They include using local water; using 50–65 percent pale or Pilsner-style malted barley and 35–50 percent raw, unmalted wheat; cooling at least 50 percent of the wort in a coolship, from near-boiling (over 180°F) to room temperature (under 80°F); 100 percent spontaneous fermentation; and others. About 40 breweries have filled out a form to use the Méthode Traditionnelle logo so far; according to Levi Funk of Funk Factory, it has been a slow process to make sure there is active membership in the group.
Wild Mind Artisan Ales in South Minneapolis uses the Méthode Traditionnelle mark and has begun producing more lambic-style beers. As in Belgium, Minnesota brewers also need the temperature to be just right for their coolships. “Most winters in Minnesota you’re going to have two windows of appropriate temperatures for coolshipping, with a period of it being too cold in the middle,” Wild Mind head brewer Ryan Placzek explains. “You get that late fall/early winter window, then a late winter/early spring window. […] We’ll continue to prepare the way we did this year, by keeping enough grain on hand and enough barrels ready, just waiting for the right overnight temps.”
An Uncertain Future for Lambic
In Belgium, ideal coolship seasons have been shortening due to changes in the climate. It’s become an issue for Brasserie Cantillon, whose operations will be “at risk by 2100 without adaptive measures like artificial cooling of the cellar,” according to climate change scientist Asa Stone.
Cantillon began production in 1900, and the current climate situation has had a bigger impact on their production than anything else in their 119-year existence, says Stone. “Brasserie Cantillon discarded 6,000 liters (51 barrels) of lambic in 2003 due to the impacts of the European Heat Wave,” she explains. “Our research also revealed that they have observed a 15-percent decline in potential brew days from 1900 to 2018.”
With more and more U.S. breweries embracing Méthode Traditionnelle, and with climate change possibly continuing to negatively affect Belgian brewers’ ability to make the same levels of lambic as they once did, the American brewing industry may be poised to become a hotbed for lambic-style beers. Austin Jevne of Forager Brewing Company in Rochester, Minnesota, adheres to the Méthode Traditionnelle rules with some of his beers and thinks it’s good for breweries to be inspired by Belgium, but that they should also branch out on their own.
“It’s another interesting stamp you can put on your bottle if you do really want to make authentic, traditional lambic here in the U.S.,” Jevne says. “Climate change is constantly affecting the natural environment around us. For us here in Minnesota, it almost works in our benefit, because if it’s getting warmer up here, […] our season will become more extended and we can produce more spontaneous beer.”
As for what’s happening in Belgium, Jevne says it’s not too surprising. “All things will change, and cultures will adapt. If Belgium can’t be producing these lambics based on the climate, hopefully there are people in areas of the world where there are the proper weather conditions who continue to honor those