Tasmania has long had a reputation as one of the country's top wine destinations.
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So it shouldn't come as any surprise that an innovative new winemaking technique is being developed right on the doorstep of the Tamar Valley - one of the state's most fertile wine regions.
Searching for ways to stabilise pinot noir, which tends to lose colour as it ages, Rosevears wine chemist Dr Angela Sparrow experimented with a stick blender – the type you might use to make soup.
Having sliced the grapes into many pieces she discovered that not only did the process result in more skin tannin and less seed tannin seeping into the wine, but also the acceleration of the maceration process.
Maceration - the process by which tannins, colour and flavour compounds are extracted from the skins, seeds and stems of a grape in a fermentation tank - typically takes between six and 10 days.
Dr Sparrow said the new technique - called 'Accentuated Cut Edges' or 'ACE' maceration - had the potential to increase the efficiency of the winemaking process by shortening the time grapes must spend in a fermentation tank.
“(When you crush grapes) you get the colour and flavour compounds coming out of the skin,” Dr Sparrow said.
“They come out of the grape skins faster where the grape has been split because they leak out of the broken cells.”
Seeking to create more skin splits in the grapes, Dr Sparrow experimented with a stick blender and found that, as planned, the blades sliced open the grape skins but left the seeds intact.
“Instead of having this one split where you squash the grape with the crusher or with your foot or whichever method you normally use, you have lots of broken edges allowing all the good stuff to come out of the grape into the wine.”
With Australia experiencing increasingly hot summers in recent decades – meaning rapid ripening seasons for grape growers - the prospect of streamlining the maceration period has excited many winemakers.
Josef Chromy Wines head winemaker Jeremy Dineen said the technique could potentially prove invaluable for winemakers battling to cope with a short harvest period.
“There have been quite a few seasons recently where lots of regions in Australia have experienced a much more condensed vintage period,” Mr Dineen said.
“Where 15 to 20 years ago (winemakers) might have had an eight week vintage, now it might be a six week vintage or similar, so you're trying to fit the same amount of production into only 75 per cent of the time.
“That's where this kind of technology could be really useful; you are speeding up the process to get the same outcome.”
This kind of technology could be really useful; you are speeding up the process to get the same outcome.
- Jeremy Dineen
Mr Dineen said while many wineries would be unlikely to abandon their own tried and tested techniques, he expected winemakers would be keeping a close eye on the technique’s development.
“It's not going to be for every style of wine, and it's not going to be for every winemaker because different winemakers have different philosophies.
“It’s very much like how different chefs will use completely different techniques for cooking or preparing or whatever it might be.”
In recent years the technique has been trialled at a number of sites in Tasmania and on the mainland, with early testing yielding promising results for appearance, aroma, flavour, structure and mouthfeel in the wine.
Dr Sparrow is now waiting on trial results before moving onto the likely next step in the process - constructing a commercial mixer big enough to process a large volume of grapes.
“I went to six wineries on the mainland and tried five different grape varieties, and all of them were very excited about pressing off early because it's going to save them space so they can get another load of fruit in.
“We had a wine tasting in Adelaide in July to see what winemakers thought and since then those wines have gone to the Australian Wine Research Institute to be assessed by their quality assessment panel. They scored the ACE wine that was pressed early from grape solids the same as the conventionally made wines that take more time to process.”
Dr Sparrow said while red wine’s long lifespan meant conclusive results were still some years away, she was confident the science behind the process was sound.
“If there's no difference between conventionally produced wine and ACE produced wine, that's good, because the ACE technique saves winemakers time and space.
“As far as the chemistry goes I'm very pleased with the results; the ACE wines look like they've got more stable colour, so if the winemaking process is likely to be more efficient, then that is a double bonus.”