Grape crop losses from smoke exposure in California in recent years may cause vineyardists who don’t carry crop insurance to reconsider, says Allied Grape Growers president Jeff Bitter.
“The reality is that not a lot of growers have previously taken advantage of crop insurance,” Bitter said during a news conference at this year’s Unified Wine and Grape Symposium in Sacramento.
“I think that’s going to change,” he says. “They’ve got all this money invested in their crops.”
Some growers in Lake and Mendocino counties received a rude awakening last summer when their grapes were rejected by several large wineries because of the potential for smoke taint.
The smoke was from the massive Mendocino Complex fires, which burned more than 459,123 acres in the region, according to the InciWeb interagency information system.
A survey last fall by the Lake County Winegrape Commission estimated that the county’s growers suffered $37.1 million in losses from smoke damage. Losses in Mendocino County are still being tabulated, the California Farm Bureau Federation reported.
Growers who had their contracts canceled because of smoke damage fears were forced to either discount their wine grape crop, make their own bulk wine out of the fruit or leave it hanging on the vine and hope their crop insurance would cover it, the Santa Rosa Press-Democrat reported.
“It was a basic stalemate” between growers and their contracted wineries, Bitter says. “In many cases their current contracts don’t have references to smoke exposure.”
Earlier this year, the Allied Grape Growers held a crop insurance seminar for growers. About 75 percent of vineyards statewide and 61 percent of them in Lake County were insured in 2018, according to the Farm Bureau.
Scientists are still trying to learn about the affects of smoke exposure on grapes, which are seen as more vulnerable than most other agricultural products because their skins are permeable. Free volatile phenols created by burning wood become part of the grape itself, University of California advisors note.
The wine country fires that spread in the fall of 2017 prompted several research projects by university scientists, including an effort by UC Cooperative Extension viticulture and enology specialist Anita Oberholster and others to examine the effect that lingering smoke from the blazes had on wine quality.
While most of that crop was already harvested by the time those fires started, last summer’s most severe blazes spread just before or at veraison, when grapes soften and change color. The risk of smoke taint increases with continual or repeated exposure to heavy smoke, so wineries were advised to test grapes to determine potential risk.
Should smoke taint be found in a resulting wine, several treatments can lessen the severity. For instance, there are “fining” agents that reduce the amount of smoke-derived volatile phenols and give wines less intense smoky characters. But those agents lack specificity, meaning they will also remove desired compounds and negatively affect wine quality, UC scientists caution.
Also, defoliation of grapevines following smoke exposure can reduce the severity of smoke taint in grapes and wine, because studies have shown that smoke-derived volatile phenols can be absorbed via the leaves and move into the fruit.
For growers who have insurance, the ability to claim a loss from smoke taint depends on certain factors, advises Domenic Fino of the Hanford, Calif.-based Ag West Crop Insurance Services. While smoke taint may not specifically be identified as a peril, there is a provision in the loss adjustment procedures that the claim could fall under, Fino wrote in an essay in October.
Two claims tests have to be met, he advises. First, elevated levels of guaiacol and 4-methylguaiacol have to be present in a pre-harvested grape tested by an independent lab. Then there must also be at least a 75 percent reduction in the value of the crop, measured as a comparison between the original contract price or average market price of undamaged grapes versus what the grower received for the damaged grapes, he explained.
Allied Grape Growers did negotiate a contract amendment for some Mendocino County growers, Bitter says. He suspects future contracts will include language regarding smoke exposure.
“Something is better than nothing, and that something needs to come out through negotiations, not a heavy hand one way or the other,” he says. “It’s a huge concern. With the large number of growers out there who don’t have smoke exposure clauses, it’s a huge concern.”