To make great wine, you need to start with quality grapes. This quality is largely shaped during the ripening period, when character, flavour and aroma compounds develop. The ripening process occurs during the warmer months, which in Australia quite often means during periods of high bushfire risk. Should the unfortunate occur and a vineyard becomes blanketed in smoke for long periods (as happened during the 2009 Black Saturday bushfires in Victoria), grape flavour can be adversely affected (think smoked bacon, cold campfires and band-aids), costing winemakers their vintage.
Researchers at the University of Adelaide, in collaboration with The Yalumba Wine Company and The Australian Wine Institute, have been investigating the impact of smoke on the composition of grapes and wine, as well as investigating new techniques to detect the extent of smoke taint in grapes and wine. As a result of this research, a number of practical solutions have been identified to help the Australian wine industry reduce the incidence and severity of smoke taint.
For example, smoke chemicals were found to accumulate in both the skins and pulp of the grape: therefore, winemaking techniques which reduced the duration of skin contact during fermentation can reduce the intensity of ‘smoke’ characters in wine. The choice of winemaking yeast and the addition of oak chips or tannins was found to also influence the perception of smoke taint in wine. As such, now when a vineyard is exposed to smoke, winemakers can make more scientifically informed decisions about how best to harvest and process their fruit to reduce the risk of producing an undrinkable drop.