Australia’s 2019–20 bushfire season has rewritten the nation’s grape and wine industry’s understanding of fire and smoke damage, leading to broad changes in the way those challenges are managed.
- The 2019 – 20 bushfire season led to estimated losses of $665 million across Australia’s grape and wine industry, thanks to fire and smoke damage
- University of Adelaide researchers found activated carbon fabric could help stop smoke affecting grapes
- Australian research into fire and smoke damage in vineyards is leading the world
The scale of damage was unprecedented in Australia — in relation to both vineyard damage and smoke taint — and the industry has estimated $665 million dollars worth of production and wine revenue was lost that summer.
Millions of dollars have since been thrown at the issue and findings from the research was pulled together at the first national wine sector bushfire conference last Tuesday [May 25, 2021].
Many of the lessons have completely changed the understanding of how to prepare for, and deal with, bushfires.
Smoke taint was first recorded in 2003, but it was believed that small, immature grapes that were yet to change colour and go through veraison [the onset of ripening] were not susceptible.
One of the big questions to come out of the Cudlee Creek fire in the Adelaide Hills was would those grapes, that were only about the size of a peppercorn, going to be be affected by smoke.
Dr Mango Parker at the Australian Wine Research Institute found that, if grapes were on the vine they would be susceptible to smoke, regardless of the size or level of maturity.
“Unfortunately, even at that unripe stage, it is possible for the grapes to take up and metabolise the smoke markers,” Dr Parker said.
Having studied three grape varieties — pinot noir, chardonay and shiraz — Dr Parker found red grapes were more susceptible to smoke taint than white varieties.
Pinot noir, in particular, suffered the most from the effects of smoke taint such as smoke, ashy smell and flavour.
The advice now is that any time a berry [unripe grape] is on the vine and smoke is in the vineyard, there is a risk.
Given research has found grapes at any stage of maturity were susceptible to smoke, University of Adelaide Professor Kerry Wilkinson looked at whether there was a way to stop the smoke being absorbed, or to remove the smoke taint from the wine so it couldn’t be tasted.
Professor Wilkinson and her team looked at several options and made a particularly promising discovery by using an activated-carbon fabric.
Grapes were enclosed in a bag made from the fabric, significantly reducing evidence of smoke exposure.
“Whereas this [fabric], we’ve tried it in a couple of different trials now.
“Every single time, consistently, we’re seeing only 1 or 2 per cent of the concentration of these smoke compounds in the grapes or in the wine where the fruit’s been protected in these activated-carbon bags, compared to where the grapes have just been exposed to smoke.”
Now the challenge is to find a way to use the activated-carbon fabric across an entire vineyard.
The combined research efforts have made Australia a global leader in the effects of fire on grapes and vines.
With climate change affecting the world’s grape-growing regions, managing director of the AWRI, Dr Mark Krstic, said the world was learning a lot from Australia’s experience.
“The events of the end of 2019 – 20 were fairly historic for the Australian grape and wine industry, in terms of the scale and magnitude of the problem,” Dr Krstic said.
Since then, Australia has consulted with a broad range of countries — including South Africa, the United States, Canada, Chile, Greece and Spain — on managing the effects of fire.
“I guess we’re about 10 years ahead of where they would be, so we’re collaborating quite closely with the researchers, particularly along the west coast of the US.”