Notes of wildfire? How some B.C. winemakers are grappling with smoke

When wildfire raged about a kilometre from the vineyards owned by Blue Mountain Winery in 2021, winemaker Mike Mavety says he knew the vintage would be difficult work. 

"It was pretty nasty," Mavety recalled of the smoke that hung over the vines near Okanagan Falls, B.C., for close to a month, just as the grapes were beginning to ripen. 

"It would have been fairly difficult to breathe … We were having to limit the number of hours our guys were out working."

But the real challenge would emerge in the fermentation tanks.   

"We went into the harvest, assuming or hoping that we would be able to do some bottling," Mavety said. 

But lab tests revealed relatively high levels of acrid smoke molecules had found their way into the fruit. So they dumped granulated carbon into the tanks with the crushed grapes, hoping it would help, Maverty said. It didn't. 

"It strips a lot of flavours and there's not a lot of ways of putting it back together," Mavety said of the aggressive treatment for what's known as smoke taint. 

Smoke taint, like the same suggests, is caused by airborne compounds from burning trees and soil that settle on grapes still on the vine. The wildfires don't have to be close to the vineyards. And it doesn't take much smoke on the grapes to affect a batch of wine.

If allowed to remain in the final product, smoke can produce off-flavours like ash, barnyard and salami. 

Ultimately, Blue Mountain chose to cancel its entire 2021 vintage. It sold 120,000 litres of wine, not good enough for its own label, to an undisclosed company for blending into other, less prestigious wines. 

"I commend Blue Mountain for what they did," said Severine Pinte, winemaker at Le Vieux Pin and LaStella Wineries, located in the same region of the Okanagan.

"There is no way to really effectively, without compromising the quality of the wine, remove the smoke taint." 

Research into ridding B.C.'s wine industry of smoke taint is ongoing. Aside from activated carbon, winemakers can resort to reverse osmosis filtration, more gentle crushing and in the case of red wines, removing the skins from the juice as soon as possible. 

But even if the wine is fine going into the bottle, some smoke molecules can sneak into the final product. If they are bound chemically to the sugars in the wine, wine makers have found they can be set free after months or years of aging.