Fire in California
University of California
Fire in California

Vineyard Resources

Wildfires can wreak havoc on your commodities directly or indirectly. Smoke damage (smoke taint) is a problem that can destroy hundreds of millions of dollars in product. However, much of the problem can be reduced through education and collaborative efforts to protect vineyards.

What is Smoke Taint?

Smoke Taint occurs when wine grapes and fruit are exposed to smoke during the growing season or during fermentation. The “taint” produces undesirable flavors ranging from “wet ashtray” to “sweaty socks” and are undetectable when tasting the fruit. These flavors ( also known as phenols) may then be released during the fermentation processes which enable even a small batch of smoke tainted fruit to contaminate an entire batch.

Smoke related issues fully develop with as little as a 30% smoke obscuration exposure for 30 minutes. While there are no known ways to remove smoke taint from the final product, there are tests available to detect the phenols associated with smoke taint. Because of the high risk of contamination from just one batch of bad grapes, if there is reason to believe smoke exposure is present, any vineyard or orchard fruit that will be fermented should be tested.

How can I reduce the risk?

Ultimately the best approach to addressing smoke taint is through prevention. With wildfire size and occurrence on the rise, take measures to protect your infrastructure, crop and products.

  • Learn your area’ s wildfire risks and conduct a risk assessment on your property.
  • Apply “Firewise on the Farm” principals to protect property and structures.
  • Create a “Fire Management Plan” for your farm that addresses your specific needs.

What do I do after exposure?

Fire - damaged crops must be tended to carefully and consistently, or you risk losing them altogether. Begin recovery of fire-damaged grapevine as soon as possible after the damage has occurred. The full extent of injuries may not fully manifest for a season, so keep tending practices regular, regardless of any positive or negative signs you might see.

  1. Repair your infrastructure. Look at trellis support systems; Inspect irrigation systems for fire damage; Remove any damaged tubing or irrigation systems.
  2. Trim scorched vines, leaves and branches. Check underneath burnt bark to see if the vine still contains viable tissue. Remember for “grafted” vines, the damaged vine must not be cut below the graft union line or else new shoots will grow from the root stock. If fire temperatures were not excessive and proper soil pH is maintained, “own-rooted” vines can be cut down to stubs and will likely re-sprout.
  3. Remove burnt leaves, vines and branches from the soil. Remove burnt patches of soil. Turn and fertilize the soil where grapevines were previously growing. Use a soil pH testing kit to determine the best fertilizer and soil to use. Water the areas of damaged soil regularly as if the grapevine were still growing there.
  4. When free of ash and debris, water the grapevine more often that you usually do. Remember, watering while ash is present can PH shock your vines or leech harmful fire byproducts into the soil. Fertilize the land around the burnt crops and continue the extra watering sessions for the entire grapevine for two to three weeks following the fire. Protect the remaining grapevines as you normally would through the end of the season
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