In addition to exacting a terrible human cost, the recent bushfires in Australia caused significant damage to the vineyards of the Yarra Valley in Victoria. And Chris Losh wonders whether the fires may represent the final straw for some of the region's beleaguered wine producers.

A couple of weeks ago I was on the phone to a friend in the South African wine industry. He was most apologetic about not having returned an earlier call but had, he explained, spent a couple of days racing around his property trying to control a bushfire that had swept down towards his vineyards.

Certainly, preventing your life's work going up in smoke seemed a more than acceptable excuse for not replying to an email.

Listening to my friend talk made the hairs stand up on the back of my neck. The randomness and potential catastrophe of the swirling flames were a terrifying combination. I could practically smell the burning bush down the phone line.

"You know," he said, "you drive around and try and look like you know what you're doing, but there isn't a whole lot you can do. Against fire like this you're really pretty helpless - it just kind of goes where it wants. You just have to hope it doesn't want to take your vineyards or your property."

Yet for all the evident fear and danger, this was strictly fourth-division stuff compared to what the wine trade has seen over the last six weeks. The major fires in South Africa were in Somerset West, not in Walker Bay, where my pal was. And even those Cape bushfires that swept over the Helderberg towards Vergelegen and Lourensford, while doubtless terrifying enough for those involved, were far less destructive than those that ripped through Victoria in February.

Wines of South Africa puts the fire damage in the Cape at "a few rows of vines and 1,000 hectares of pine forest, with no fatalities". But the conflagration in Victoria took 80ha of vineyard, burned three small wineries to the ground and claimed 200 lives. And all this just 45 minutes' drive from the centre of Melbourne.

"It's one of the worst tragedies to affect Victoria, let alone the wine industry," says Brett Fleming, European manager for the Rathbone Wine Group. "The human cost is horrific. Then you've got the economic cost."

The current estimate is that about 5% of the Yarra Valley's total area under vine has been directly affected by the fire. In some sub-regions, such as Upper Gouldburn, half of the vineyards will not harvest a crop at all this year.

Yet the collateral damage could be far worse even than this. As tragic and soul-destroying as it must be for the owners of the 29 vineyards that have been ruined by the fire, the most damaging element is likely to be smoke-taint affecting the grapes.

Smoke-taint is a complex and not fully understood phenomenon that the industry is only just starting to get to grips with. Growers in Victoria are being encouraged to submit samples of vines, grapes and juice to the Australian Wine Research Institute's analytical service, which has promised a three-day turn-around on the results.

The early indications are not encouraging. The official scientific line is that "a single heavy exposure of smoke to grapevines is sufficient to result in smoke taint in wine ...  grapes that have repeated smoke exposures or smoke exposures for a long period of time produce wines with an accumulation of smoke aromas and compounds".

Moreover, as the Australian Wine Research Institute puts it, "low concentrations in grapes at harvest is not a guarantee that any wine made from those grapes will be free from smoke taint." In other words, we can analyse your grapes, but in the end, frankly, who knows?

Dozens of wineries which were not directly affected by the fires could find themselves with tainted fruit that is, effectively, worthless. A lot of ostensibly healthy grapes may not be picked at all this year.

Of course, it might not be so apocalyptic. The two signature 'fire smoke' compounds, guaiacol and 4-methylguaiacol, are nothing if not mercurial. They can hide away in bottles for years before appearing ten years down the line, or never show at all.

"We had bushfires in 2008, and there's no perceivable issues with those wines even though we had smoke blowing through the vineyards for weeks," says Brett Fleming. "So we're pretty confident that you won't see any smoke taint this year. Though we've still got to make the wines and find out."

Whatever the level of smoke taint, the timing of the inferno that engulfed parts of the Yarra in February could hardly have been worse, coming, as it does, at a time of reducing consumption, of reduced willingness of banks to lend, and on the back of two already tricky vintages.

The 2008 harvest was a naturally massive crop that saw prices tumble, while 2007 was hit by frost, fire (again), locusts and even a tornado. The poor Yarra growers must be wondering just what they've done to incur so much celestial wrath, and it would be understandable if some of them, surveying their blackened rows, simply walk away.

"Smaller boutique, family wineries are certainly struggling, and the recent drought and heat-related effects will no doubt be the last straw for many," says John Beresford, viticulturalist and winery manager for Mitchelton Wines.

It's to be hoped not. The Yarra, ironically one of Australia's coolest wine regions, is home to some of the country's most interesting wines, of the sort that will help to improve the Aussie image abroad. If the country ever needed its famed battling spirit to show through, it's now.

"The only way this industry is going to recover is by selling its wines," says Fleming. "We have to hope that the buyers and retailers buy into that philosophy, too. We need as much help as we can get."

Amen to that...