Drought and high temperatures negatively affect hop crops: they advance maturation, reduce plant production and the concentration of alpha content – ??the acid that gives beer its bitter taste – by 0.6% from of 1994. For this reason, the scientific community predicts that climate change will be able to worsen the quality of beer – in addition to reducing its production – if “immediate adaptation measures” are not taken.
This is the conclusion of a study published in the journal Nature Communications, led by Martin Možný, researcher at the Global Change Research Institute of the Czech Academy of Sciences.
The analysis has focused on the main hop-producing regions of Europe, such as Germany, the Czech Republic and Slovenia, countries that include almost 90% of the continent’s total aromatic hop field area. The results obtained indicate that, with regard to 1994, the production of hops has decreased by 0.2 tons per hectare and per year. In addition, maturation has been advanced by an average of 20 days.
“The specific aroma of hops arises from the content of bitter acid; therefore, changes in bitter acids affect the quality of hops; and there has been a recent variation in consumer preference for beer aromas and flavors that depend, in large part, on high-quality hops,” the study specifies.
The study estimates that by 2050, due to heat and drought, hop yields could be reduced by up to 31%; and, in the case of alpha content, the decrease could reach 18%. In the case of the most optimistic climate scenario, the declines would be 4% and 20%, respectively.
In Germany, the Czech Republic and Slovenia, declines are expected to be more pronounced in the south than in the north of the country. However, it is estimated that the most important productive impact will be in Slovenia, Portugal and Spain, where the yield loss of hop crops could reach 35%.
“The critical situation in Spain derives fundamentally from the lack of water resources and authorized products for the fight and control of diseases, which cause serious productive losses”, says Javier J. Cancela, member of the Project and Planning Research Group (PROePLA) of the University of Santiago de Compostela.
Farmers in different countries have responded to climate change and relocated hop crops to higher altitudes, built irrigation systems, and even developed more resistant varieties. However, one of the most important climate change risks raised by the study is that “high-quality aromatic hop crops are restricted to relatively small regions, where environmental conditions are suitable”.
For this reason, and since it is believed that droughts will increase, “it will be necessary to expand the cultivation area by 20% compared to the current area to compensate for a future decrease in production”. Cancela argues that hop varieties need to be improved. The goal would be to increase their tolerance level for biotic (eg disease) and abiotic problems, such as droughts and heat waves.
