Earth, Wind and Fire: West Coast vineyards are now faced with the challenge of smoke-tainted grapes

Illustration by Joel Hedstrom

Illustration by Joel Hedstrom

It has been a horrifying couple of seasons of wildfires in both California and Oregon wine country. Vineyards have had to ensure their harvests deliver a product free of “smoke taint,” which occurs when wood burns and releases a compound called guaiacol that can drift on the fiery winds, onto grapes, and through their skins. At high levels, this compound can create flavors of tar and burnt ash—and not in a good way.

In Oregon, many growers were in a bind after California-based Copper Cane LLC canceled their grape-growing contracts for fear of high smoke taint from the 2018 Klondike fire, leaving them with millions of dollars worth of fruit. This is rather controversial, given that the effects of smoke taint are largely unknown—grapes must be tested to see if they contain guaiacol, and the effect can vary from grape to grape. Ultimately, the truest way to see if the grapes produce an unappealing wine is by making one—which is precisely what several Oregon winemakers did: they came together to purchase and test the fruit. Their 2018 Oregon Solidarity Rosé of Pinot Noir has sold out, as has their Chardonnay which garnered 90 points from Wine Enthusiast.

The research on smoke taint is currently limited. One thing that has become clear is that grapes are most susceptible to smoke just after veraison (when the color change occurs in red grapes, typically just before harvest). It’s also been shown that red grapes are at a greater risk of smoke taint contamination than white grapes.

UC Davis’ legendary enology program is on the forefront of this research. The goal is to develop better guidelines for understanding smoke taint, to create better wine from smoke-affected grapes and ultimately protect the economics of winemakers and grape growers. One method discussed at the 2018 Innovation + Quality forum, which is dedicated to developing techniques to advance wine quality, was “Flash Detente,” a vacuum and vaporization method proven to have some smoke-mitigating effects. However, more trials are needed to see more conclusive and, ideally, pleasing results.

The vineyards themselves remained mostly unscathed from the worst of the fires, as their higher moisture content acts as a natural firebreak. The grapes can’t escape the smoke, however. As a changing climate leads to more extreme weather this research will become increasingly important to the future of West Coast wine.