Forest fires and exposure of grapes to smoke has become a major winemaking issue. The key compounds responsible for the aromas are volatile phenols, guaiacol, 4-methyl-guaiacol, and many others, and are found on the outer (cuticle) layer of the grape. The smoke taint compounds exist in juice and grapes in the glycosylated form. Winemaking practices can release the odorous free volatile phenols, as can time and subsequent acid hydrolysis. Unfortunately, juice may taste acceptable, but during fermentation and over time may develop more serious smoke taint issues.
There are a number of winemaking techniques that can be used to reduce the effects of smoke in wines, and these are more valuable when used in combination. The following recommendations are based on current knowledge of how to reduce or mask smoke character, however, there are no known processes to completely remove all smoke compounds from a wine.