Australia — 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 the findings, part of a $4million smoke taint study, will lead to better timing of controlled burns and the creation of an online interactive tool that will help winegrowers assess the likelihood of their grapes having been damaged by smoke.
The research, undertaken at the Department of Primary Industries research centre in Irymple, near Mildura, vastly increases the number of chemicals in smoke that are known to taint wine.
While the science of smoke taint is far from fully understood, 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 after the Alpine 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, and ash kind of aroma and taste. And in taste it had a very metallic and strong flavours at the back of the tongue. And because of these unpleasant flavours and aroma people didn’t like it,” he said.
Agriculture Minister Peter Walsh said a range of grape varieties at different growth stages would be subjected to smoke in the research. The berries and the wine they made would then be analysed.
”The breakthrough will give producers a better idea of whether their grapes have been tainted and to what extent they are affected. It will help them avoid future losses so they are not investing money in producing wine only to find out later it is unsaleable because it is affected by smoke taint,” he said.
De Bortoli winemaker Steve Webber said research into smoke taint was necessary.
”There’s just no question, we’ve got to have more of an understanding of it. I think this is a nice start,” he said.
Mr Webber said bushfires in Australia affected grapes in a different manner to the experience of overseas bushfires and vineyards.
”It’s those compounds that come from the gum trees that we believe are the things that cause the problem,” he said.
In 2007 De Bortoli’s King Valley property was severely hit by smoke taint.
”We virtually lost the entire harvest up there with smoke taint. Drought also affected us in the same year, so it came in twos that year,” he said.
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.