Researchers from UBC Okanagan created a spray to protect grapes from wildfire smoke. Wildfire smoke contains volatile phenols that can be absorbed in ripening grapes and impact their flavor. In 2003, Austrailia wildfires cost the wine industry $300 million. Researchers believe that the wine industry is on track for the same results in 2020.

When wine grapes absorb compounds from smoke, the grapes react by coating the compounds in sugar using their enzymes. (Source: UBC/iStock)

Wildfire season in California and the Okanagan Valley has been increasing in severity and length in the last few years. Because of this, winemakers need to protect their crops from harmful smoke. When wine grapes absorb smoke, the grapes react by coating compounds in sugar with their enzymes. The sugar-coating masks the smoky odor and volatile phenol taste. Phenols are released again during fermentation. Currently, the only way to find if a grape has been affected is to ferment the fruit. Farmers have to wait weeks to know if their plants are suitable for wine or not.

One solution is to purchase grapes outside of the affected region. But many wineries pride themselves on growing their own grapes locally, so sourcing outside of their fields isn’t an option.

The team found that wine grape’s flavor can be protected from wildfire smoke by applying an agricultural spray made of phospholipids, typically used to prevent cracking in cherries. To test the spray, the team sprayed wine grapes and exposed them to simulated forest fire smoke one week later. The results showed that the spray reduced levels of volatile phenols.

The team’s next steps are to work on replicating and refining the result to alleviate crop losses.

A paper on this research was published in the Journal of Agricultural and Food Chemistry.