Climate change making beer worse — but wine better

'Beer drinkers will definitely see the climate change, either in the price tag or the quality.'

Climate breakdown is already changing the taste and quality of beer, scientists have warned.

The quantity and quality of hops, a key ingredient in most beers, is being affected by global heating, according to a study. As a result, beer may become more expensive and manufacturers will have to adapt their brewing methods.

Researchers forecast that hop yields in European growing regions will fall by 4-18% by 2050 if farmers do not adapt to hotter and drier weather, while the content of alpha acids in the hops, which gives beers their distinctive taste and smell, will fall by 20-31%.

“Beer drinkers will definitely see the climate change, either in the price tag or the quality,” said Miroslav Trnka, a scientist at the Global Change Research Institute of the Czech Academy of Sciences and co-author of the study, published in the journal Nature Communications. "That seems to be inevitable from our data.” 

Beer, the third-most popular drink in the world after water and tea, is made by fermenting malted grains like barley with yeast. It is usually flavoured with aromatic hops grown mostly in the middle latitudes that are sensitive to changes in light, heat and water.

Hop yields

In recent years, demand for high-quality hops has been pushed up by a boom in craft beers with stronger flavours. But emissions of planet-heating gases are putting the plant at risk, the study found.

Beer is the third-most popular drink in the world after water and tea.

The researchers compared the average annual yield of aroma hops during the periods 1971-1994 and 1995-2018 and found “a significant production decrease” of 0.13-0.27 tons per hectare. Celje, in Slovenia, had the greatest fall in average annual hop yield, at 19.4%.

In Germany, the second-biggest hop producer in the world, average hop yields have fallen 19.1% in Spalt, 13.7% in Hallertau, and 9.5% in Tettnang, the study found.

The taste of beer does not just depend on the hops, but it explains part of the drink’s popularity, said Trnka. “Across the pubs of Europe, the most frequent debate except weather and politics is about the … beer.” But weather and politics are both changing the taste of beers.

A beer surrounded by hops, wheat and barley used to make it. 

As temperatures rise and rainfall dwindles, some hop farmers have moved gardens higher, put them in valleys with more water and changed the spacing of crop rows.

Trnka said: “Growers of hops will have to go the extra mile to make sure they will get the same quality as today, which probably will mean a need for greater investment just to keep the current level of the product.” 

Fine wines

Meanwhile, on a brighter note for drinkers, it has been found that warm temperatures and higher rainfall — both of which are expected to become more common with climate change — are the key to producing good wines.

Experts led by the University of Oxford analysed 50 years' worth of wine critic scores from the Bordeaux region of France and compared them with that year's weather.

The results suggested higher quality wine was made in the years with warmer temperatures, higher winter rainfall, and earlier, shorter growing seasons — conditions that are expected to become more frequent with climate change.

Study author Andrew Wood, from the Department of Biology at the University of Oxford, said: "Weather drives wine quality and wine taste.

"We found evidence that temperature and precipitation effects occur throughout the year — from bud break, while the grapes are growing and maturing, during harvesting, and even over winter when the plant is dormant."

The research, published in the journal iScience, concluded that as the "climate continues to change, the quality of Bordeaux wines may continue to improve".

The researchers also said they suspect their results will apply to other wine regions.

'With climate change, generally we are seeing a trend across the world that with greater warming, wines are getting stronger.'

For the analysis, the team looked at climate data and annual wine critic scores from Bordeaux between 1950 and 2020.

They chose Bordeaux because it is a wine region that relies on rainfall for irrigation and there is a wealth of wine critic score data and merchant wine score data.

Experts examined how the weather influences wine quality at both a regional and local scale.

Overall, the researchers found Bordeaux wine quality scores tended to improve between 1950 and 2020.

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Bordeaux's climate warmed over that period but the team suggested better wine-making or adjustments for consumer likes and dislikes may also play a role.

Mr Wood said: "The trend, whether that's driven by the preferences of wine critics or the general population, is that people generally prefer stronger wines which age for longer and give you richer, more intense flavours, higher sweetness, and lower acidity.

"With climate change, generally we are seeing a trend across the world that with greater warming, wines are getting stronger."

The team found that weather impacted wine quality throughout the year, not just during the growing season.

They also found high-quality wines were produced with cooler, wetter winters; warmer, wetter springs; hot, dry summers; and cool, dry autumns.

Mr Wood said: "With the predicted climates of the future, given that we are more likely to see these patterns of warmer weather and less rainfall during the summer and more rainfall during the winter, the wines are likely to continue to get better into the future."

But he warned they may only improve up to a point.

"The problem in scenarios where it gets really hot is water: if plants don't have enough, they eventually fail, and when they fail, you lose everything," he said.

"But the general idea or consensus is that the wines will continue to get better up to the point where they fail."

Guardian and PA