Does the golden drink have a bitter future?
Hops are one of the main components of the beer, giving it its characteristic bitterness. However, climate change could seriously compromise the cultivation of hop and its quality. A team of experts led by Martin Možný from the Czech Hydrometeorological Institute and including Vojtěch Vlach from the Department of Physical Geography and Geoecology at the Faculty of Science, Charles University, has given a glimpse of the possible future of this golden beverage through a study published in the journal Nature Communications.
Nowadays, beer is one of the most popular beverages after water and tea. Its quality is also directly related to the quality of the input ingredients. Apart from water, the main ingredients are malted barley, yeast, and the above-mentioned hops. Hops determine the characteristic bitter aroma, which is the result of bitter acids and many other compounds, including essential oils and polyphenols. Unlike in the past, today there is a high demand for hops with a higher content of α-acids, which determine the bitterness, flavour, and shelf-life of beer. However, climate change could significantly affect its quality and overall production if the sector is unable to adapt to the change.
A group of experts studying the impact of climate change on agriculture therefore set out to analyse the probability of yield, α-acid content, and cone development of European hops between 1970 and 2050. All of this was predicted by a 1.4 °C increase in air temperature and a 24 mm decrease in precipitation. The detailed research focused on Germany, the Czech Republic, and Slovenia, where almost 90% of all European hop-growing areas are concentrated.
Climate change is already having an impact on the quality and cultivation of hops. Heat waves and extreme droughts in particular have a negative impact. When comparing the period before and after 1994 (up to 2018), hop ripening started approximately 20 days earlier, with a decrease in production of almost 0,2 t/ha/year, and the α-acid content decreased by approximately 0,6%, which determines the high aromaticity of hops. Hop-growers are already trying to adapt to these changes by moving hop-growing areas to higher altitudes and valley positions with higher water tables, building irrigation systems, changing the orientation and layout of crop rows, and even by breeding more resistant varieties, but the question is how far this will go and what the hop quality will be.
To further assess the effect of changing weather conditions on the yield and α-acid content of aromatic hops, the authors developed a simple model simulating changes in precipitation and temperature differences compared to optimal conditions during the growing season. Model projections for 2021–2050 indicated a projected decrease in hop yields of 4–18% compared to 1989–2018; α-acid content decreased by as much as 20–31% by 2050 in the projection scenario.
The results of this study bring unpleasant, yet expected news for the possible future quality and quantity of traditional aromatic hops in Central Europe. Unless immediate adaptation measures are put in place to ensure the stabilisation of this growing global industry, we could be left with a bitter drink we can only dream of.
Kateřina Fraindová
Published:
Nov 10, 2023 06:05 PM
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