Finding perfect time to grab grapes off the vine
Studying viticulture, eco-gastronomy and the science of wine
As climate change threatens other winemaking regions in the world, a new two-year study aims to pinpoint the perfect time to harvest grapes on the West Coast.
These findings may transform the emerging coastal industry, says lead researcher and University of Victoria ecologist John Volpe.
“The novelty of our approach stems from the use of a specific type of molecular analysis,” said Volpe, who is also a certified sommelier. “We expect to gain insights on how to make great wine at a resolution never before available and it will help growers harvest with confidence.”
That’s why the study plans to identify markers of the “best” time to harvest, by combining spectrometry technology with changing the conditions for the grapes at three British Columbian vineyards to test for changes in flavour chemistry.
As wildfires burn across the province of B.C., prompting heightened discussions about the long-term effects of climate change, winemakers are left mitigating changing weather conditions and its effect on the grapes.
“As climate continues to change and ripening patterns change, particularly here on the coast where at one time we were on the edge of getting grapes to ripen,” Volpe explained, “we are now seeing a significant change where ripening is not a problem.”
Even heat-loving varieties of grapes are becoming more common in B.C., he added. That raised the concern for winemakers about finding the “perfect time” to harvest.
Grapes have two kinds of ripeness: sugar and physiological. While the first is easy to distinguish by taste, growers cannot determine what kind of wine it will make, Volpe said. The latter refers to the “hundreds of flavour compounds” locked up in the grape — and not released until after fermentation — which are at peak diversity and density, he added.
Currently, vineyards use a “best guess” approach by testing for sugar ripeness.
“The challenge, then, is to ask, when do you harvest,” Volpe explained. “Are there changes that can be made to allow winemakers better insight on when to pick grapes?”
Physiological ripeness has a brief peak — but then it declines. Yet, it’s the best measure for the tastiest wine, Volpe added.
The field work will be conducted at Blue Grouse Estate Winery, Unsworth Vineyards, and Enrico Winery, where researchers will test changes to the diversity of flavour compounds.
Volpe said the supply and quality of wines around the world is “very much in flux,” noting traditional grape grow- ing countries such as Italy or France are experimenting with growing different grapes as weather conditions change.
But that has some benefits for other markets, he added, who now have a potential to grow different varieties.
“The challenges facing this emerging industry is that it has yet to meet its potential,” he said. “Given the changing external environment, that potential continues to rise.”
Coastal winemakers can now grow varieties seen in warmer temperatures, such as sparkling wine, Volpe added.
Initial data for the study is being collected this summer by Andrew Watts, a masters student. Wine Islands Growers Association president Lamont Brooks said it’s an exciting opportunity to bring scientific rigour to measuring ripeness.
“This important new knowledge will allow our winery businesses to continue to produce and improve the crisp aromatic wines so characteristic of our growing area,” he said.
The project was supported by WIGA through programs delivered by the Investment Agriculture Foundation of B.C., which receives funding from the Government of BC and Agriculture and Agri-Food Canada programs. Preliminary findings are expected by spring, with the study wrapping up by 2020.
And across the province, Okanagan wine producers are facing serious challenges with rising temperatures — grape vines “shut down” at 35 C — and taint from wildfire smoke.
But the island “can handle more heat,” Volpe said. Grape varieties that weren’t formally an option, are now.