Climate change: How a warming planet could affect the taste of B.C. wine

Yahoo

24-05-2025

Future sommeliers may have something very different on the nose, as climate change alters the taste of wine in regions around the world.
A global study led by UBC researchers, and published this week in the journal PLOS Climate, found that temperatures during the grape-growing season have increased across the world's major wine regions — including B.C. — and that the heat is changing the taste of wine.
For the study, researchers analyzed temperatures over the growing seasons in wine regions on five continents and studied 500 varieties of grapes. They studied the temperatures during dormancy, budding, and during harvest.
The climate data will eventually allow scientists to recommend which varieties of wine grape are best suited to the changing climate in different regions, including those with unique climate challenges such as intense heat waves, drought and wildfire smoke.
'We want to be able to say to growers, OK, there's 1,000 varieties out there. Here are some recommendations on which ones to consider,' said Elizabeth Wolkovich, senior author of the study and an associate professor at UBC's faculty of forestry.
On average, the regions have warmed by the equivalent of almost 100 extra growing degree-days, a measure of the cumulative heat that vines are exposed to, according to the study.
Impacts of a hotter climate include lower grape yields, heat damage to berries and vegetation, and an industry that is rapidly working to adapt, the study says.
Speaking Friday from Zurich, where she is working with colleagues who contributed to the global study, Wolkovich said this heat can affect harvest times and grape ripening, which changes the taste of the wine.
'Most of the wine you drink from Europe and North America is already a different flavour profile due to climate change than you drank 30 or 40 years ago. The biggest obvious change is that the grapes are more sugar rich, and that means they are also higher in alcohol,' she said.
As the weather gets warmer, the grapes develop faster. For instance, she said the grapes are ripening in parts of France in late August instead of September.
'When they ripen in late August, and are exposed to hotter temperatures, the grapes build up sugar faster. The grapes you harvest have higher sugar acid ratios, so the balance in the wine is different.'
The acidity, which gives the wine its zest, declines in warmer weather while pigments in wine called anthocyanins, which give the wine its colour, break down. Tannins may not develop if the grapes are plucked too early to compensate for the heat.
'I would say it would taste a little bit more like jam, or what you would call like a fruitier wine, and it would maybe be generally a little darker, less light in the flavour profile, and, on average, a little bit less complex for a red wine,' she said, but emphasized that expert winemakers are skilled at compensating for this change.
Around the world, scorching heat, wildfires and other climate-related disasters have already decimated crops, including here in B.C.
The province's wine industry is still recovering after two years of climate-related crop losses in the southern Interior. Record-breaking heat, wildfires and smoke tainted grapes, while a destructive cold snap in 2023 and 2024 caused significant crop loss across the province.
Varieties of grape most affected in B.C. were Syrah, Merlot and Cabernet Sauvignon, with projected losses of more than 65 per cent, according to a report last year from Wine Growers B.C.
Wolkovich said there are hundreds of varieties in Spain, Italy and Greece 'that you've probably never heard of' that could work well at some point for B.C. growers as the heat intensifies. One example is Xinomavro, a wine grape that tolerates the dry heat of Greece.
The difference is Mediterranean regions like Greece have longer growing seasons than B.C. so the trick is to find varieties that have a shorter ripening time but are also heat-resistant.
On that note, Wolkovich also said there are varieties from the mountainous regions of Spain that B.C. growers haven't tried that could work well as the temperatures increase.
'So regions in Spain that are at higher elevations have shorter growing seasons, but they also are hot — the way the Okanagan is hot. And I know that certain vineyards have looked into them and would love to try them.'
She said the problem isn't that the consumer won't want to drink these hardier varieties, but that there are hurdles in Canada to importing the rootstock.
Kathy Malone, chair of the B.C. Wine Grape Council research and development committee, said winemakers are wary of testing new varieties when it takes years for the grapes to grow and mature in flavour.
Malone, who is also a winemaker at Hillside Winery and Bistro in Naramata, said there are efforts underway to get experimental plots going in B.C.
'You could have very small plots of varieties that no one's ever heard of and make a small amount of wine, but then you could blend that into another wine.'
She said it's very difficult for B.C. winemakers to make decisions about new varieties that will be cold-resistant and that the focus should be on the warming climate and what varieties will survive intense heat.
After last year's cold snap, Hillside will be planting the Malbec variety, which is less cold-hardy than Merlot but will do much better under the increasingly hotter Okanagan summers.
'I don't think there was much Malbec planted in the 80s and 90s, because it requires longer hang time and more heat. But now we're getting that heat more and more,' she said.
'The seasons are expected to be hotter and longer moving north. In some areas, like in Napa, it's a challenge because it's too hot and they have berries drying up on the vine.'
For the study, scientists developed climate metrics for the world's wine regions that spanned the annual plant cycle of a calendar year.
They found the biggest impact is in southern and western Europe, where the number of days over 35 C is the highest of all regions, with nearly five times as many extreme heat days compared with 1980.
'The temperature increases here (in B.C.) aren't as dramatic as in Europe, which is something that as a community, we're still trying to understand,' said Wolkovich.
Growers are testing methods to adapt. Some are using shade cloth to protect vines from heat while others are planting new rootstocks and varieties.
The study also looked at regions affected by wildfire smoke and how widespread fires in Australia led to technologies and approaches that could be used in California or in B.C.
For example, some winemakers are now installing sensors in the vineyard to know when smoke is about to affect the grapes.
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With files from The Canadian Press
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