Winemakers Test For Smoke Damage

Vintners have developed more sophisticated tools to test whether  wildfire smoke has tainted grapes.

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The wildfires that ravaged California and the Pacific Northwest have lost ground as the wet autumn weather has helped quell the blaze. But much of the damage has already been done, with more than 30 people dead and tens of thousands of homes and businesses burned. 

But the fires threaten to claim another victim: the wine industry. 

“I heard the horror stories from California and I was worried sick,” says Kiley Evans, winemaker at 2Hawk Vineyard & Winery in Medford. Like many vineyards in the southern part of the state, the grapes at 2Hawk were blanketed by smoke, which has the potential to affect the flavor of a wine. 

When grapes are exposed to smoke, compounds can seep through the skin of the fruit. This gives the wine an ashy, bitter flavor. There are no known health hazards to drinking wine that has been tainted by smoke. But a crop that has been severely impacted could become unsellable. 

For white wine, smoke damage is not as much of a problem. White grapes are taken out of the skin before fermentation. This means the damage is less than for red grapes, which ferment inside the skin.

New testing methods for smoke damage help winemakers see in advance whether their crops are tainted, allowing them time to salvage the grapes.  

In 2013 a winemaker testing for smoke damage would take a sample of grapes to a lab where the fruit would be pureed in a blender and tested. Results from these tests were less than accurate. The contamination levels present in the sample would be between two and eight times the level of contamination actually present in the wine. 

But testing methods have improved. Smoke damage has become a greater concern in the industry. Now winemakers test for smoke damage by fermenting a small portion of wine ahead of time. This new style of test yields more accurate results about the crop.

“Thankfully you’ve got a lot of science geeks in the winemaking business,” says Evans. 

If a wine is revealed to be too contaminated, all is not lost. Winemakers could choose to use their red wine grapes for rosé. Rosé grapes are removed from the skin prior to fermentation, mitigating the damage. If results are borderline, a winemaker could make their decision based on the style of wine. Smoky notes are more common in Malbec and Shiraz, but could be more detectable in smoother varieties. 

Despite having to undergo fermentation ahead of schedule, the new tests are able to be performed prior to harvest. In California however, wine testing labs face a backlog of demand. If the same holds true for Oregon, winemakers could be facing a great deal of uncertainty as they wait for results. 

Evans was relieved when the results of his test came through. It showed smoke contamination as expected, but the degree was less than feared. On a scale of one to ten, Evans says the smoky notes are a “three or four.” Although an experienced wine drinker might be able to detect the flavor, the decision was made to harvest and ferment as planned.

Even if test results show low amounts of contamination across the state, the real danger could be in perception. If Oregon wines get a reputation of being damaged by smoke like some vintners in California, purchasers could look for cases elsewhere. 

Given the widespread prevalence of wildfires, it could be difficult for buyers to find vineyards without some degree of smoke damage. Wildfires are becoming routine along the West Coast. The ability to mitigate, test for and adapt to smoke damage could be a new frontier for the wine industry. 

“Everything west of the Rockies has a wildfire burning somewhere,” says Evans. “It’s like one giant science experiment. The wildfires are generating wine research dollars like coronavirus is generating health care dollars.” 

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