Breakthrough identifies smoke tainted grapes

Until now, the unpleasant burnt taste in wines caused by smoke taint has been very hard to manage as winemakers could not tell whether grapes were affected until well after the wines were made and often sold. But a breakthrough announced this week has identified thiophenols as the offending molecule.

When a fire breaks out near a winery the winery can be bathed in smoke. The grapes absorb the smoke taint and it binds with sugars meaning the flavours can not be tasted. But once fermentation has occurred the taint can become volatile although it can months before the full effect of smoke taint can become known. Chemical analysis of grapes or freshly made wines has not been possible because no one has known what molecule causes the smoke taint.

Elizabeth Tomasino, an associate professor of enology at Oregon State, made the discovery in conjunction with Washington State University as reported in Physics.org. The hope is that growers will be able to test grapes before harvest. If the grapes are not suitable all the costs of harvest and wine making can be saved.