(Reuters) - Wildfires sweeping through southeast Australia are carrying with them the specter of a silent killer for grapes growing in the nearby Adelaide Hills wine region.

The vineyards have so far escaped the direct ravages of the worst bushfires for 30 years but winemakers fear their grapes may have fallen victim to "smoke taint", which results in wines that taste like an ashtray and can ruin an entire vintage.

As fears grow that climate change is lengthening the time and severity of Australia's bushfire season, government funding to find a solution to the phenomenon is drying up.

"It's a nightmare of a problem," said Mark Krstic, a specialist in smoke taint at the Australian Wine Research Institute who is liaising with worried growers in the Adelaide Hills in SouthAustralia state.

"Smoke taint is one of the symptoms of climate change for the wine industry and it's only getting worse."

Smoke taint first caught the industry's attention when Victoria state's severe bushfires in 2003 cost grape growers more than A$7.5 million ($6.05 million) in lost vintages. Since then, it has recurred in vintages around the country in four other years.

The contamination occurs when smoke compounds enter vines through the stomata - the minute pores in the epidermis of the leaf - and are transported into grape skins.

Those compounds are then released into the wine when the crushed grapes come into contact with the skins during fermentation. Tasters commonly liken the resulting wine to an ashtray, burnt rubber and hospital disinfectant.

Grape growers with tainted crops have two options - abandon the vintage or continue the costly harvesting and fermentation process to make a significantly devalued product.

"It's a no-win," said Chris Pfieffer of Pfieffer Wines in the Rutherglen wine region, who lost his 2003 crop to smoke taint.