A leading Belgian artisan brewer said he has been forced to temporarily halt production because of an unusually warm autumn, blaming climate change for night-time temperatures that are too warm to produce beer.
The Cantillon craft brewery in Brussels traditionally allows its spontaneously fermenting sour lambic beers to cool in the open from the end of October, but this year after a brief start they have had to stop again.
“We had to pour away three brews for today, Thursday and next Monday because the night-time temperatures are currently at between 50-59F, which is far too warm,” boss Jean Van Roy told AFP news agency.
Like many breweries in Belgium, Cantillon, which produces around 400,000 bottles a year and receives 50,000 visitors, uses old-fashioned methods to produce its beers.
Lambic spontaneously ferments in wooden vats and produces a very sour, flat beer that later acts as the base for a fizzier Gueze that ferments further in bottles.
It is also used as the base for Kriek, the famed Belgian cherry beer.
Tradition dictates that the fermentation mixture must be left to cool “in the open air so that it is naturally infused with the wild yeasts present in the air”, said Mr Van Roy, whose great grandfather founded the brewery in 1900.
“Ideally it must cool at between minus 3C and 8C. But climate change has been notable in the last 20 years. My grandfather 50 years ago brewed from mid-October until May – but I’ve never done that in my life, and I am in my 15th season.”
The brewing period is getting shorter every year, he added.
“Last year we didn’t start until November 10,” he said, adding that they never go past the end of March. “I adapt because I don’t have any option, but obviously it’s a shame.”
Mr Van Roy said he now feared for the future of his business.
“We only have five months to brew and our production is very limited. If we lose a week we can survive but three weeks or more would be more complicated.”