It pays to keep cool with sauvignon
BY DEBORAH WALTON AND PETER MORICE
Auckland scientists studying the unique characteristics of New Zealand sauvignon blanc have shown that cold storage can triple the shelf life of the wine by reducing the loss of characteristic tropical fruit aromas over time.
Associate professor Paul Kilmartin, of the wine science programme and department of chemistry at the University of Auckland, says that New Zealand sauvignon blanc has a variety of styles and aromas, but wines from Marlborough in particular are known and valued for their intense tropical fruit and herbaceous aromas.
"It has been widely accepted that these aromas are lost with age and that the wine, which has traditionally been stored at room temperature, is best enjoyed young," he says.
Until now, most research has focused on the dangers of oxidation, such as whether or not it is beneficial to use screwcaps or add antioxidants to the wine.
"We have shown that, in fact, temperature is the most important consideration in retaining fruity characteristics during storage," says Mr Kilmartin.
To cite just one example of how cool temperatures work in favour of keeping the flavour in sauvignon blanc, researchers from the University of Auckland's wine science programme have shown that two aromatic compounds, called thiols, which impart passionfruit, grapefruit and herbaceous aromas, are present in particularly high levels in New Zealand sauvignon blanc.
The first phase of the current research showed that in commercial wines stored at room temperature, levels of the less stable thiol declined about 40 per cent in the three months after the wine was bottled and were almost undetectable after two years. These changes seemed to be unrelated to exposure to oxygen. Levels of the second thiol increased briefly and then declined slowly, while a number of fruity esters also declined rapidly in the bottle.
The second phase of the research, studying commercial wines stored at a range of temperatures for 18 months, showed that the rate of loss of the less stable thiol and other fruity esters was three times lower at five degrees Celsius than at 18C. This confirmed that the change in aroma profile over time was very dependent on temperature. The results showed that sauvignon blanc under refrigeration retains its desirable characteristics for much longer and this has important implications for consumers and how they go about getting the best from their wine. Store your sauvignon blanc in the refrigerator but don't drink your white wine too cold – bring it up to "just cool" before consuming, otherwise you dumb down the flavours.
This finding sheds some light on why some Hunter's 2000 single vineyard sauvignon blanc, which had been left in the back of the drinks fridge for 10 years, came out tasting absolutely stunning.
The fruit flavours were rich and reminiscent of stone fruit and the overall taste was rich and well integrated.
Woven Stone Ohau Sauvignon Blanc 09
This is the second time we've had the opportunity to taste wine from Ohau, New Zealand's newest grape-growing area.
Woven Stone is named for the signature gravel-stone remnants in the vineyard, crushed and shaped by the force of the Ohau River, Horowhenua (just north of the Kapiti coast). Take those stones and add in the region's flax-weaving heritage and you come up with Woven Stone – a second-tier label from Ohau Gravels that threads the strands of local history with a new wine.
Aroma: Pungent, zesty, grassy, herbaceous, some capsicum notes and an underlying tropical whiff – think figs, really ripe passionfruit, pineapple and tree tomato notes. The aroma is quite rich and complex – a good start ...
Taste: There's plenty of punch due to the taste of ripe fruit. The rich tropical fruitiness is tempered by some brisk acids and some lovely grassy, green apple flavours that last to the finish and aftertaste. There's some heat to this wine – the label says 14 per cent and we can believe it – the wine lacks balance due to that lingering alcoholic heat.
Some time in the bottle will allow for integration and really, this is a minor niggle. This is an exciting new wine worth a try – it has already done well in the Air New Zealand and Bragato wine awards, garnering silver medals.
Price: Good buying at $16.99.
Riverby Estate Sali's Block Marlborough Riesling 08
Aroma: Limes and kerosene, straw and summer grass, some melon and light stonefruit notes round things out.
Taste: A lip-smacking flavour burst – sweet lemon perfectly balanced with some kerosene flavour glides effortlessly into some rich stonefruit and citrus at the finish and aftertaste. Ripe, refined and very enjoyable – this wine was made with a blend of botrytis and "clean" fruit to create the natural sweetness that makes this wine so moreish.
Price: A must-have at $20.
- The Marlborough Express