Chill out, and enjoy your wine

Wine drinkers already know sauvignon blanc tastes best if chilled, and scientists have now proven keeping it on ice helps retain its flavours.

But the results could vary depending on how the wine was stored before it was sold.

The research, part of the Sauvignon Blanc Programme, a collaboration between Auckland and Lincoln universities and Plant and Food Research, shows that keeping the wine cooler reduces the loss of its characteristic tropical fruit aromas.

Professor Paul Kilmartin of Auckland University's chemistry department, who is working on the research, said it was widely accepted that intense tropical fruit and herbaceous aromas were lost with age and the wine, which has traditionally been stored at room temperature, was best enjoyed young.

But the research shows that storing the wine in a cooler environment retains the aromas for longer.

"Well-managed refrigeration could help to improve the consistency of quality wines sold here and overseas, and allow the wine industry to cope with changes in supply and demand from year to year," Dr Kilmartin said.

Earlier research showed that two aromatic compounds, called thiols, which impart passionfruit, grapefruit and herbaceous aromas, are found in high levels in NZ sauvignon blanc.

When wine was stored at room temperature, during the first phase of research, chemical tests detecting the presence of 3MHA, the least stable of the two thiols, showed it declining by about 40 per cent in the three months after the wine was bottled. It was almost undetectable after two years.

The changes appeared to be unrelated to exposure to oxygen.

A second thiol, 3MH, declined slowly but a number of other fruity esters declined rapidly in the bottle.

During the second phase of research studying wine stored at a range of temperatures for 18 months, the rate of loss of 3MHA and other fruity esters was three times slower at 5C than at 18C.

Waiheke winemaker Chris Canning said 70 per cent of New Zealand's wine was sauvignon blanc, the "single variety produced on a factory scale".

"So to refrigerate the enormous 100,000-litre tanks is a very costly exercise and probably, for the winemakers, no longer possible because most of those tanks are outside."