Scientists have identified more than 20 chemicals that make smoke-tainted wine taste like leather, disinfectant and other unpalatable flavours in a new research project that aims to limit the damage to the wine industry caused by smoke.
Researchers hope that the findings, part of a $4 million smoke taint study, will lead to better timing of controlled burns and the creation of an online interactive tool that will help wine growers assess the likelihood of their grapes having been damaged by smoke.
The research, undertaken at the Victorian Department of Primary Industries research centre near Mildura, vastly increases the number of chemicals in smoke that are known to taint wine.
The industry has long known that wine grapes do not need to be exposed to smoke for long to be damaged.
Senior research scientist Davinder Singh said the problem of smoke taint emerged in the wake of the devastating bushfires of 2003 which caused some vineyards in north-eastern Victoria to be affected by smoke for about three months.
''When they made the wine out of it, it had a very unpleasant aroma and taste - like bacon and barbecue, disinfectant, leather, an ash kind of aroma and taste. And in taste it had a very metallic and strong flavour at the back of the tongue. And because of these unpleasant flavours and aroma people didn't like it,'' he said.
Smoke seems to affect different varieties differently, Dr Singh said. The differences could be due to the type of grape, but also to the manner in which the wine is made, he said.
Dr Singh nominated Sangiovese as a variety that seemed to ''accumulate as much smoke chemicals as possible'' in its skin and more than other reds like Cabernet Sauvignon and Shiraz.
De Bortoli winemaker Steve Webber said the business lost almost the entire harvest at one of its properties because of smoke taint in 2007.
Two years later, smoke from the Black Saturday bushfires had a substantial impact on De Bortoli's Dixons Creek vineyard in the Yarra Valley. Mr Webber said it was important to know if the chemicals in smoke from bushfires had the same impact on grapes as the chemicals in smoke from prescribed burns.