A single-engine water bomber returns to Okanagan Lake for more water during efforts to fight a wildfire in Kelowna, B.C., on July 23, 2015.DAN RIEDLHUBER/Reuters
The question
Please don't laugh. But I'm curious, will all the smoke from the Okanagan wildfires affect the grapes' flavours? Do the leaves or grapes absorb substances that land on them?
The answer
Nothing to laugh about (especially not the fires). It's a good question, and the answer in this case is: probably not. You're not the first person to write in with this question. Others have wondered whether the smoke from the tragic wildfires this summer in British Columbia's Okanagan Valley will impact the flavour of wines once grapes are harvested and crushed. It would hardly be the worst outcome of the blazes that have already destroyed many homes and which continue to pose challenges for firefighters in various parts of the province.
But to answer your question, smoke has mainly stayed clear of the vines. The flames that came close to vineyards in the South Okanagan in August were met with mercifully light winds. This permitted smoke to rise up rather than to move across the land and settle on grapes.
In principle, smoke can indeed impart smoky or even metallic flavours to wine. This is particularly problematic as grapes ripen in late summer and early autumn, when skins become softer and more absorbent, as occurred with some crops in 2003. Some wineries back then, such as CedarCreek, chose to discard some of their harvest because smoke was so intense.
Red wines are especially susceptible because they are fermented along with their skins. The juice for white wines, in contrast, is separated from the skins prior to fermentation, and the skins are simply discarded.
Any foreign substance sitting on skins can potentially affect a wine's flavour if it gets into the fermenting vat. You may recall the unusual Niagara harvest of 2001, when a swarm of Asian ladybugs infested vines. The tiny pests secreted a substance that spoiled a vast amount of the harvest with overly herbaceous flavours and even an essence that some described as reminiscent of rancid peanuts. And mould, always a threat when rains are heavy during harvest, can spoil wine. That's one reason most wineries employ sorting tables to separate good berries from bad.
The Flavour Principle by Lucy Waverman and Beppi Crosariol (HarperCollins) won top prize for best general English cookbook at the 2014 Taste Canada Food Writing Awards.
E-mail your wine and spirits questions to Beppi Crosariol. Look for answers to select questions to appear in the Wine & Spirits newsletter and on The Globe and Mail website.