If talk of rising sea levels and more frequent natural disasters doesn’t terrify you into caring about climate change, perhaps this will: Rising global temperatures could have a negative effect on traditional Belgian lambics. (Cue beer nerd panic.)
When Brasserie Cantillon posted on Facebook earlier this month that it had to cancel two brew days this week because temperatures were too warm, it sparked a minor freakout. Cantillon allows native yeast and bacteria to float into its cooling beer wort, but if temperatures are too warm, it allows other, less desirable bugs to creep in.
“It is important for lambic brewing to have temperatures below 10-12°C (50-53.6°F) at night. 8° C is better for a quick cooling,” Frank Boon of Brouwerij Boon, another Belgian lambic producer, told me in an email. “In general it is not a problem from 1 Oct until 30 April. But the start of this November was the warmest we ever had. I cannot speak for the Cantillon brewery, but as the night temperatures in the center of the city are about 4° C higher than in the countryside, they will be the first to be confronted with it. If the temperature is too high, lambic will be overgrown by thermobacteria, resulting in difficult fermentations with too much acidity. That is why we never brew lambic in the summer months; the effect is the same.”
So is traditional lambic production doomed? Not quite. A couple of days after its initial Facebook post, Cantillon updated anxious fans: “No worries, no risk of less production this season yet… We are stopping for one week only, weather [sic] forecast are correct for the coming weeks!!!”
Boon told me his brewery hadn’t experienced any temperature issues yet: “Yesterday night it was freezing; this morning temperature was 12°C,” he wrote on Nov. 4.
So, for now, it seems our precious lambics are safe, with no drop in production expected this year. If global temperatures continue to fluctuate wildly in the coming years, though, effects on traditional open lambic cooling could be serious, to say nothing of what that would do to global barley, wheat and hop production.