What is Smoke Taint?

What is smoke taint? And why are winemakers concerned?

All of us in California are aware of major fires that typically occur in the Fall when conditions are the driest and winds prevail. We all wish fires would not occur but lately, every Fall, the sky appears hazy and the air smells like smoke. We heard someone just off the plane smelling the smoky air say, “ Wow, it smells like California!”.

The concern for vineyards and wineries is the damage smoke can cause to grapes. When vineyards and grapes are exposed to smoke, the results in wines can be undesirable sensory characters. These undesirable sensory characteristics are known as smoke taint with descriptive flavors of “ashtray”, “medicinal”, “campfire”, “smoky”, or “bacon”.

The cause of and impact of smoke taint isn’t always cut and dry. The freshness of the smoke and proximity to the fires are factors. Even certain grape varieties can be more prone to smoke damage. To further complicate matters, similar vineyard sites that have similar smoke exposures may not equally be affected.

Smoke taint is caused by a wide range of compounds found in wildfire smoke, which once absorbed by vines and accumulated in berries, will remain there through processing. One can’t predict which grapes may have suffered damage based on anything intuitive, such as sight, smell or even the flavor of fresh grapes.

There are several options for wineries that fear smoke-damaged fruit. The first is to sample grape berries and have them tested. Since this process is not very accurate, the second option is for wineries to carry out small scale fermentations. Once fermentation is finished a chemical analysis can help predict the likelihood of smoke taint in the wine. However, tasting and sensory evaluations on the wine are even more important.

If a wine has been fermented and it has been determined through lab analysis and sensory evaluation to have smoke damage, there are a couple of options to treat the wine. The first is to pass the wine across a membrane that releases the smoke bound molecules from the wine. The second is to treat the wine with enzymes then use reverse osmosis to remove the smoke molecule. Both of these processes have been shown to help and in some cases make a positive difference. However, whether one is successful depends on the wine.

On August 14, 2021, in the Sierra Foothills, the Caldor Fires started and expanded quickly burning thousands of acres, destroying a community and causing evacuations in many others. Andis Wines and others in the Shenandoah Valley got lucky as we experienced no smoke damage and harvested grapes that showed no smoke taint. Our wines for the 2021 vintage were unscathed and we expect another excellent vintage.

Cheers!
Mark Fowler, Estate Winemaker, Andis Wines
Janis Akuna, Executive Winemaker, Andis Wines