SYDNEY - Australian scientists say they have identified the substance that gives some red wines a distinctive peppery aroma, a discovery that could have major implications for the multi-billion dollar wine industry.
The aroma, often found in fuller-bodied wines made from shiraz or cabernet sauvignon grapes, was until now assumed to be linked with climate.
Certain wine-growing areas, such as the Barossa Valley in South Australia, seemed to yield reds with that characteristic.
But the discerning noses of scientists at the Australian Wine Research Institute have produced a different story.
The fragrance, they say, emanates from a single compound, known as alpha-ylangene, and previously unrecognised.
One researcher, Margo Parker, told a wine industry conference that a single drop of it would make an Olympic-sized swimming pool smell peppery.
Ms Parker said the discovery might enable wine-makers to control the bouquet of reds, in the same way that they alter a wine's characteristics with different yeast varieties or oak barrel fermentation.
If you can measure something, you can understand its behaviour and how to control it," she said. Scientists spent eight years trying to work out what gave shiraz wine, in particular, its spicy aroma.
Alan Pollnitz, a senior researcher, said: "The aroma has always been found in some shiraz, but not others, some regions and not others, some vintages and not others."
They isolated the potent compound, which has a concentration of one part per billion, using sophisticated instruments such as a mass spectrometer.
But old-fashioned methods proved most effective.
"At the end of the day, a lot of people did a lot of sniffing throughout the research," Ms Parker said. "Our noses were our most sensible and reliable detectors."
Shiraz is by the far most popular red wine variety in Australia, accounting for one-fifth of the industry's entire sales.
The peppery fragrance was found in about 70 per cent of shiraz wines tested by researchers, and 30 per cent of cabernet sauvignon.
Dr Pollnitz called the discovery of the compound "a very significant breakthrough, perhaps the most significant in a generation".
But one of Australia's biggest wine-makers turned his nose up at it yesterday.
Bruce Tyrell, owner of Tyrell's vineyard, told The Australian newspaper that "the more commercial end of the market" might be interested in controlling a wine's bouquet.
"But at the top end I'm inclined to take what nature's given me," he said. "I don't ever want the wine to become Coca-Cola. The soil and the climate will win in the end."
- INDEPENDENT