BELGIUM

CONTINENTAL DRIFTER
Belgium: there’s airborne yeast in my beer!
by Elliott Hester
click on photos for enlargements

My tour ended with a sip of cherry beer. Then another sip. This was followed by unpretentious gulps that ended with a cherry-flavored burp. When I finished the bitter-sweet cherry beer, or “Kriek”, I was offered a glass of “Blanche” (white) beer. The white beer—named for the cloudy sediment formed during fermentation—tasted refreshingly sour.

The sipping and gulping was part of a “beer tasting” held six days a week, several times a day at Cantillon Brewery in Brussels. Established in 1900, the family-run business produces 900 hectolitres of Lambic beer per year. In beer-crazy Belgium, where some 100 breweries produce more than 400 different varieties of beer, Lambic is perhaps the most unusual. During my visit to Cantillon Brewery, I learned why.

The self-guided tour led me through eight stages of the Lambic brewing process. I stopped first at the mashing house, where wheat and barley are mixed with warm water to create a sugary liquid known as “wort.” At station No. 2, the wort is mixed with dried hop flowers and cooked in 19th-century red copper boilers.

I climbed the stairs to the attic and peeked into the granary (station No. 3), where sacks of hops, malted barley and wheat are stored during the brewing season (Oct. – Apr.) Stations five through eight deal with beer maturation, barrel cleaning, bottling and barrel storage. But at station No. 4, the most unusual aspect of Lambic brewing takes place.

With traditional beer brewers, yeasts are added manually to ferment the wort. But with Lambic beer, wild airborne yeasts—present in the atmosphere in and around Brussels—are allowed to permeate the wort naturally.

Here at Cantillon, 7,500 liters of wort are pumped into a huge, shallow, copper tub called a “cooling tun.” The tun sits beneath an open-sided roof, exposing the wort to the elements. After a chilly winter night, airborne yeasts are naturally deposited into the wort. It is then poured into untreated wooden barrels. Days later, as the wild yeasts and wort react inside the barrels, spontaneous fermentation occurs. Voila! You have Lambic beer.

Airborne yeasts aren’t the only natural aspects of Lambic brewing. Harmful insects, attracted by fermentation and fruit (fresh raspberries, cherries and grapes are added to Lambic to create fruit beer), infiltrate the brewery during summer. Along with the unsavory insects, come creepy-crawly guardians: spiders.

“Spiders maintain a biological equilibrium in the brewery by eliminating all harmful insects.” So says the eleven-page information booklet given to visitors at the start of the self-guided tour. “A Lambic brewer never destroys a cobweb and killing spiders is considered ‘not done’.”
Because of flying yeasts and spiders, Lambic producers remain exempt from European Union hygiene regulations that govern traditional brewers. It’s a good thing, too.

I like my beer cold. And my yeasts, airborne.

Next stop: Girona, Spain

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