Smoke Taint Workshop

Abstract

An increasing number of cases of taint caused by smoke from bushfires and controlled burning to reduce fuel loads in parks prompted Wine Australia to convene a workshop to discuss industry concerns.

Summary

The format chosen was a one day workshop held in Melbourne. It was attended by people from Victoria, South Australia and Western Australia. In addition to presentations by industry representatives and researchers there as input from the Bureau of Meteorology about changing climate and bushfire trends. Topics ranged from an overview of the last vintage and impacts of smoke from bushfires, to analysis of smoke-derived volatile compounds, aroma thresholds, and possible methods of treatment of wine affected by smoke taint. To get close to the problem smoke-affected wine was offered for tasting at lunch.

A key component of the day was to list what was known and not known about the problem. Growers and winemakers present were pleased to learn that there was no carryover effect of smoke taint and that it was safe to burn bush after harvest but not happy to hear that taint compounds are durable once in wine, getting worse with wine age. It was pointed out that the peak in sensitivity existed from seven days post veraison and that smoke also affected yield and photosynthesis. It is also known that there are differences in varietal sensitivity and that white wines having less time on skins are less affected. Another “known” is that problems exist in analysis, with some samples of wine not recording the presence of offending compound suspects guaiacol and 4-methylguaiacol yet exhibiting characteristics of affected wine. Among unknowns listed were importance of smoke intensity, the full story about offending compounds, the best practical ways of reducing impacts in the vineyard and the mode of entry of these compounds.

What the workshop meant to the industry was the opportunity to explain problems, get an update on research and have questions answered by people working on the problem. The discussion also resulted in recommendations for further research.