THE DAMAGE CAUSED by the wildfires in California was devastating in its immediate impact but there is still the issue of smoke taint and how much crops will be affected by it. Researchers may have found a powerful tool that could help to limit the future impact of the smoke. Researchers from the University of British Columbia (UBC) have developed a new chemical test which can accurately measure the levels of damaging compounds grapes absorb when they are exposed to smoke. Affected grapes absorb and metabolize volatile phenols – aromatic chemical compounds – which can severely affect the taste of wine further down the production line.
“Until now, detecting these smoky compounds in grapes required fermenting a small sample over at least ten days and relying on subjective measures like taste and odor,” said Wesley Zandberg, assistant professor of chemistry at UBC. Using a series of chemical tests with local vineyards in British Columbia’s Okanagan Valley wine region, Zandberg said that the researchers were able to not only isolate the metabolized volatile phenols, but also measure them to a high degree of accuracy. Under a standard timeframe growers must wait for up to two weeks to find out whether their grapes are fit for use, but the latest development could allow growers to see instant results. The test detects the exact amount of volatile phenols present in the grape so there’s no need to ferment them first. By knowing precisely whether and by how much a particular crop has been impacted by smoke exposure, winemakers can make a better informed decision over whether the grapes should be used.
The test also has additional benefits for winemakers as many growers intentionally add volatile phenols to their wine by using smoked oak barrels in the ageing process. According to Zandberg the chemical tests can also be applied to the grapes which have been fermented to measure phenol levels in the wine itself, allowing wineries to control the level of smoky flavor. “This could be hugely beneficial in helping winemakers determine whether wines have enough smoky compounds to match their desired flavor profile after ageing in smoked barrels,” he said.