3 February 2025
With several bushfires currently burning in western Victoria, smoke has been observed drifting from these fires across other wine regions in Victoria, NSW, Tasmania and South Australia.
The AWRI helpdesk has received a number of calls from producers about the presence of smoke in their vineyards, including from producers located a long distance from the fires themselves.
Grape and wine producers who are concerned about the possibility of this drifting smoke affecting their grapes are encouraged to contact the AWRI helpdesk (helpdesk@awri.com.au or 08 8313 6600 phone option 1 followed by option 1) as a first step to discuss their observations, concerns and potential management options.
Where there are multiple concerned growers in a region, it may be sensible to collaborate and coordinate an initial sampling program from across the region, in conjunction with the local regional association, to assess the risk through diagnostic testing.
In general, AWRI advises sampling grapes for smoke analysis three weeks prior to harvest to allow time for transport of samples, analysis and receipt of results before making harvest decisions. Tips for sampling, packaging and transport of grapes for smoke analysis are available in the fact sheet: Grape sampling, processing and transport following vineyard smoke exposure.
Growers located close to bushfires are advised to contact their preferred laboratory to coordinate testing of samples. Information about Affinity Labs’ smoke testing is available from: https://affinitylabs.com.au/smoke-analysis-wine/
What do we know about smoke composition and the amount of smoke exposure that causes smoke taint in grapes?
Smoke is made up of particulate matter, secondary organic aerosols and volatile phenols and other compounds. The exact amount of smoke exposure that will result in a perceptible smoke character in wine is not well known, as the chemical composition of smoke reflects fuel and combustion conditions and changes rapidly in the atmosphere, becoming lower in the concentrations of volatile phenols over time. This means that smoke from recently burnt woody materials will contain higher concentrations of free volatile phenols, and thus have greater potential to cause smoke taint in grapes and wine. The density of smoke particulate matter can be measured. However, a relationship between measured particulate matter and the risk of smoke taint has not been determined conclusively.
More information about smoke taint is available on the AWRI’s smoke taint webpage
Acknowledgement
This eBulletin is supported by Wine Australia, with levies from Australia’s grapegrowers and winemakers and matching funds from the Australian Government.
