It was a bushfire year and the wine showed some smoke taint, but for esteemed winemaker Brian Croser the Hunter Valley burgundy remains one of the best drops he has ever tasted.

Key points: Winemakers are being urged to process grapes from smoke affected regions

Winemakers are being urged to process grapes from smoke affected regions The 2020 vintage is shaping up to be an excellent year for most districts

The 2020 vintage is shaping up to be an excellent year for most districts Some winemakers are looking at how they can use smoke tainted grapes to innovate and change perceptions

The Adelaide Hills winemaker is now urging growers in smoke affected regions across Australia to not abandon their fruit on the vine, with the promise of an excellent vintage across most areas.

"You can produce a good wine from a bushfire year and not only that, you could see that the wine had been affected by bushfire," Mr Croser said.

"It had a smoky aroma and taste but it was pleasant — you know some people like single malt whiskey which has the same taste.

"We as winemakers employ charred barrels to get some of the same taste into wine, and that's not to forgive the really ashtray-like smoke flavour that you get, but it might surprise many people to learn that this year is turning out to be a really, really good year for most wine districts in Australia."

While a small number of growers had grapes that were beyond redemption and would produce a strong flavour akin to a wet ashtray, the vast majority of fruit would be suitable and winemakers should be encouraging their use, he said.

"If you pay to pick it, we'll make it and then we can sort it out later," he said.

Winemakers say this year's difficult vintage thanks to the bushfires could provide new opportunities for innovation. ( Unsplash: Kelsey Chance )

'Testing is not foolproof'

Mr Croser said there was no established correlation between the results of smoke taint testing in laboratories and the final result in a wine.

He said the Australian Wine Research Institute was a global leader in research done into smoke taint, but there was still a lot to learn and there was merit in winemakers crushing grapes to see what came of this year's vintage.

"Wine has to be made from smoke tainted grapes to really appreciate if it's spoiled or not," Mr Croser said.

"Testing is not foolproof — there's still a lot of suck it and see, or perhaps I should say sniff it and see."

Tainted fruit a 'mystery box'

For Adelaide winemaker Samuel J Smith, the catastrophic bushfires that have burned across eastern and southern Australia have provided a fresh challenge.

The small scale winemaker, who operates from a shed in a vineyard in McLaren Vale, has called out to Australian wine grape growers who have smoke-affected grapes, offering to buy small parcels of tainted fruit at full market price.

Winemaker Samuel J Smith plans to test how smoke tainted the grapes are using his garage chemistry lab set up. ( Supplied: VHS Wines/Instagram )

"I played around with [smoke] a few years ago just in terms of trying to get guaiacol — in terms of the smokiness you get in an oak barrel," he said.

"We started smoking the fruit with American hardwoods — cherry wood, maple and apple — and from there we developed a niche market for smoky aperitivo-style wines and it kind of just grew from there.

"A lot of the growers that I've worked with previously would essentially drop fruit as soon as they realised there was smoke taint through their vineyard.

"We really wholesomely believe that there is a market for those styles of wines and it's really just educating the consumer that we can produce wines and I think we can produce very interesting wines from blocks of smoke tainted fruit."

Mr Smith described his style as "molecular oenology", a spin off of Spain's El Bulli's famed school of molecular gastronomy which combines science and theatre with technical know-how.

"We coined that term a couple of years ago — we didn't really know what we were doing and I guess that term got thrown around a little bit on the back of molecular gastronomy," he said.

"We use a lot of crazy chemistry to make little tweaks and adjustments."

Mr Smith said the wine being made from the smoke tainted fruit was a "mystery box" and would most likely be blended with other wine to soften its intensity.

"It's kind of exciting for us because we can twist it and play with it a little more, there's always things we can do, and if it gets to the stage where it's beyond reparation in terms of the wine quality we will just send it through the distil process and make a really cool vermouth out of it," he said.

Some Adelaide Hills wineries "lost everything" in the December fire. ( Supplied: www.gofundme.com )

Smoke taint could be far beyond bushfire hit areas

Tony Battaglene, chief executive of the national association for winemakers and growers, said growers from wine regions across three states were testing their grapes, with the threat of smoke taint not isolated to areas where the bushfires occurred over summer.

"It's been pretty widespread, so it's gone right across New South Wales, right across Victoria, as well as South Australia, so it's gone very much over the country so it has the potential to cause major damage," he said.

"You can test two weeks before you harvest and that gives a good idea of the extent of the smoke taint.

"You can distil it, you can feed them to cattle, you can do any other use, but if it's tainted, we don't want to see it going into wine."

But he emphasised how resilient the industry was, and the greater environmental threats being faced by growers.

"Probably what people don't understand is the drought and the lack of water is probably having a bigger affect on the vintage than the actual smoke taint so you need to put it in proportion," he said.

Vineyards were impacted across premium grape growing regions across three states. ( Carl Curtain )

An opportunity to learn and innovate

The Hunter Valley was significantly impacted by bushfires in New South Wales, with wineries not directly impacted by fire now just weeks ahead of the 2020 vintage and facing up to the uncertainty of how smoke might have affected their grapes.

Last month, one of the region's biggest producers, Tyrrell's, announced the company would not be harvesting most of its vineyards, bringing their grape crush 80 per cent below their normal amount.

At Tulloch Wines, two tonnes of shiraz grapes have been picked and are fermenting in buckets.

It is well short of the 50 tonnes that would normally be brought in to the winery but the shiraz will be used primarily for testing and gaining a better picture of how the bushfires affected the fruit.

But chief executive Christina Tulloch said it was possible the shiraz could end up being bottled.

"I wouldn't say no — let's see what happens and there might be an opportunity to do some other fun things with it," Ms Tulloch said.

She said this year provided an opportunity to winemakers to try and innovate.

The Hunter Valley has been significantly impacted by bushfires in the lead up to the 2020 vintage. ( Stewart Ewen: Supplied )

"This is not going to be the last year we deal with smoke taint and we've seen some amazing things be done around natural wines so I think we just need to open our minds to the fact that these wines are not traditionally perfect but that doesn't mean we can't make something great out of them and explore something different," Ms Tulloch said.

"That's where great stuff comes from, when you try something different.

"What is great to one person is offensive to the other … I think there is a real opportunity to recognise there is a spectrum of tastes so there is a good chance some people will like the tastes or the marketing spin that someone puts on this different style of wine."

What is smoke taint?

The main culprit of smoke taint is volatile phenols, strong smelling compounds that are produced when wood is burnt, that are absorbed by grapes and bind to grape sugars.

It is not until fermentation that they really become apparent in wine, releasing a range of traditionally undesirable flavours from bacon fat through to wet ashtray.

These flavours can continue to evolve right up to the first sip of a wine.

Using laboratory analysis and small-scale ferments, grape growers and winemakers can work out whether their grapes have been exposed to smoke, and how significantly it may be expressed in the final product.

This may determine whether grape growers harvest their fruit, or leave them on the vines.

The South Australian Government has announced it will fund free testing for growers in the Adelaide Hills and Kangaroo Island ahead of harvest which is due to begin in a matter of weeks.

Those in the industry hope that many of the grapes from the Adelaide Hills will have escaped the dreaded smoke taint, with the Cudlee Creek fires occurring before the crucial onset of veraison, when the grapes ripen and develop sugars.

Low sugar means a reduced ability for volatile phenols to bind to the fruit.