Belgian sour beer is at risk from climate change — here’s why

Belgian beer styles became a hit with consumers around the world in the past year, but environmental scientists in Brussels claim that climate change could make the sour serve extinct, putting artisan brewers out of business.

(Photo: MediaProduction/iStock)

Climate change scientists working on beer research site lambic.info have said that rising temperatures in Brussels and the Pajottenland region south-west of the Belgian capital — where Lambic beer is produced — could cost brewers thousands as their stocks develop bezomerd, a coloquial term for overexposure to heat, or “too much summer.

Lambic beer is made using wild yeast, and fermented in the open-air in order to react with bacteria present in the atmosphere. Many brewers rely on the natural environment to regulate temperatures, cooling their beers overnight in conditions ranging between -8 and 8C. The beers, which are brewed between October and April, and then stored in wooden barrels and must be aged below 25C.

But lambic.info’s researchers, in partnership with Belgian beer firm Cantillion, found that the window for brewing in Brussels has shortened by around 15 days since the 1990s, as climate change has forced temperatures to rise worldwide, and predicted the window could become even shorter in the years to come, according to Belgian website BeerCity.

Mark Stone, one of the scientists behind the research, said: “(Cantillion’s owner) pulled together the brewing records for us going back into the 1930s and we could see it was tightening up.”

“You could see that they were able to brew into October and April consistently in the past. For Jean, because of warmer autumns and springs, that sort of window is impossible now.”

“The threat of climate change on traditional lambic production at Cantillon is indicative of the broader issue. That is, the impacts are not fully recognised until a threshold has been crossed, and adaptation strategies often exacerbate the problem while delaying the inevitable.”

Jean Van Roy, who owns brewer Cantillon — which produces 400,000 bottles of Lambic beer annually said that artificially cooling the beer would alter its flavour profile, and incur heavy production costs.

“If tomorrow I would have this problem every season, financially it could be a bit difficult, so we would have to change something.”