European beer under climate change threat

The authors of a Nature Communications study have called for urgent adaptation measures to stabilise international market chains after the study projected that European beer producing regions will experience reductions in hops yield and hops acids.

After water and tea, beer is world’s most widely consumed beverage and the world’s most popular alcoholic beverage. In addition to water, malting barley and yeast, beer is flavoured with hops which contain alpha acids that give the beer its unique bitter aroma and also affect its quality.

Since the cultivation of high-quality aroma hops is restricted to relatively small regions with suitable climate and environmental conditions, there is a risk that climate change will affect production. Currently, little is known about the possible effects of a predicted warmer and drier climate on the yield and alpha content of hops.

Lead researcher Martin Mozny and colleagues collected data on beer hops yield and alpha content between 1971–2018 from 90% of European beer hops growing regions in Germany, Czechia and Slovenia. They found that hops ripening has been starting 20 days earlier since 1994, production has declined by almost 0.2 tonnes per hectare each year and hops alpha bitter content has decreased by about 0.6%.

Combining past data with climate models, the authors estimated that European beer growing regions would see a 4–18% reduction in traditional aroma hops yield and a 20–31% reduction in hops acids by 2050. The largest declines are expected to occur in the southern hop growing regions, such as Tettnang, Germany and Celje, Slovenia. These declines are said to be caused by rising temperatures and more frequent and severe droughts, according to the models.

The authors suggest that traditional beer hops farming practices should be adapted to alleviate the negative effects of climate change in Europe.

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