Climate change will worsen the quality of beer, but improve wine. Scientists’ research

Despite global efforts, greenhouse gas emissions from human activities continue to increase average temperatures. There are many indications that the key barrier of 1.5 degrees Celsius will be exceeded in the next five to seven years.

Hop inflorescences, popularly called cones, are – next to water, yeast and malt – the fourth key ingredient necessary for beer production. They are added before the brewing process to increase bitterness, or only later to change the overall taste. Hops also have preservative properties in the finished beer. In particular, the boom in the strong-flavored craft beer industry has increased demand for high-quality hops.

Scientists from the Czech Academy of Sciences (CAS) and Cambridge University compared data from 1971–1994 and 1995–2018. According to their analyses, European hop yields are decreasing. In some key hop-growing areas, production dropped by almost 20%. According to experts, warmer, longer and drier summers will make the situation even worse and may result in an increase in beer prices.

At the same time, the content of hop alpha acids, which influence the bitter taste of beer, has decreased due to higher temperatures, and by 2050 it may decrease by up to 31%.

Martin Mozny from CAS, co-author of the article, warned hop growers that failure to properly adapt cultivation techniques would threaten its profitability in some areas. The consequence will be lower production and higher prices for breweries.

Remedial measures recommended by experts include moving crops to higher ground where there is more rainfall and installing irrigation systems. However, further investments and an increase in the area of ​​hop cultivation by approximately 20% will probably be necessary.

In the case of wine produced using the same methods from grapes of a variety still growing in the same vineyard, its quality often varies from year to year. As scientists from the University of Oxford have proven, the weather plays an important role.

After analyzing 50 years of detailed meteorological data (1950-2020) and the assessments of sommeliers from the Bordeaux wine region in the southwest France, researchers have shown that higher quality wine is produced in years with higher temperatures and earlier, shorter growing seasons with warmer, wetter springs, hot and dry summers, cool and dry autumns, and cooler, wetter winters. Such years together with climate change there will be more and more.

Overall, wine quality in Bordeaux has shown a trend of improvement between 1950 and 2020. While this may have been due to the warming climate during this period, the increasing use of technology in wine production during this period or producers adapting their techniques to consumer preferences may have also played a role.

The researchers focused on Bordeaux because it is a exclusively rainfall-fed wine region and has a long-term record of wine quality. Wine grading is subjective and unblinded, which means that wine critics know the origins of the wines they taste. However, because most critics agree on which wine is “good” and which is “bad”, the authors argue that quality is a “non-subjective property of perennial crops” that can be used to monitor crop changes over the long term.

Unlike previous studies that only focused on weather during the growing season, this study also examined the impact of weather during the winter. As first author Andrew Wood of the University of Oxford said, quoted by the BBC, “We found evidence that the effects of temperature and rainfall occur throughout the year – from bud break, grape growth and ripening, through to harvest and even overwintering when the plant “is in a state of rest.”

“The trend – whether driven by the preferences of wine critics or the general public – is that people generally prefer stronger wines that mature longer and provide richer, more intense flavor, higher sweetness and lower acidity,” Wood pointed out. – “Overall, with climate change around the world, we’re seeing wines getting stronger as it warms.”

As climate change creates favorable weather patterns for wine quality in Bordeaux, the authors say the quality of wine from the region is likely to continue to improve. But only until the rainfall decreases.

According to the authors of the publication, the results obtained can be applied not only to wines from Bordeaux, but also to other wine regions. They plan to conduct further research to confirm this. They speculate that annual weather fluctuations and climate change also affect the quality of crops from other perennial crops, such as cocoa and coffee.