Corked Or Corkless: Trends In Wine Bottles

The common perception that one in 10 bottles of wine is corked is wrong, according to a recent research. The results of a study into wine taint - the first independent research of its kind in the world - has just been revealed, debunking a few myths. The research was carried out by the Wine and Spirits Association (WSA) of UK, who put together a joint working group for the study, comprising a consortium of 19 companies and the Campden & Chorleywood Food Research Association. The study showed that up to 1.2 per cent of wines were corked, when unofficial figures have put the percentage at 10 times that. How did things get so skewed? The WSA's John Corbett Milward gave this theory: "The figures have been chucked about over the years. Bits are added on here and there, and suddenly you've got a figure that isn't anywhere near the truth.

Based on anecdotal evidence, between five and 12 per cent of wines are supposedly corked, but, as this report reveals, this blatantly isn't true." The study was based on 13,780 bottles of wine from 17 countries, including France (33 per cent of samples), Italy (11 per cent) and Australia (nine per cent). Problems other than cork taint were also monitored, such as oxidation, which accounted for most defects. In all, 3.4 per cent of wines were found to be ‘commercially significantly defective’.

Oxidation defects were similar in synthetic and cork closures, but verified mustiness (corkiness) occurred only in samples with cork closures. There was a ‘significantly reduced incidence of mustiness in wines bottled in 2001 and non-vintage’.

This, says the report, could be due to advances already made by the cork industry, or that the taint hasn't had time to show itself yet. White wine suffered the majority of cork taint. However, it is not so easy to detect cork taint in red wines with all their chewy tannins. One curious outcome was that cork taint was lowest in Italian wines. When most of the world's cork comes from Spain and Portugal, what are the Italians doing differently? " I have no idea", says Corbett Milward. "Clearly, there is more work to be done."

The Australian Wine Research Institute has undertaken a long-term study into different closures. This study, published last year, has won the respect of winemakers around the world. According to David Gleave, managing director, Liberty Wines, London, "The WSA's study will win little respect. The WSA's definition of ‘commercially significant’ needs to be looked at closely. The majority of wines tainted by cork show little evidence of ‘mustiness’ or, more accurately, TCA, or trichloranisol, the compound that imparts this musty flavour to wines. Instead, their flavours are muted, something which leaves the consumer feeling that the wine rather than the bottle is not very good.

For the producer, shipper and restaurateur, this is very commercially significant for they have failed to provide the customer with the quality for which they paid.

These cases of muted wines can be identified only if a control sample is available, ideally one sealed under a neutral closure such as screw or crown cap.

This did not take place in the WSA's study, something, which makes a mockery of its claim that 3.4 per cent of the wines were tainted.

In our experience, says the Australian study, the level of tainted wines is much higher. For this reason, Liberty Wines is urging its several of its producers to bottle their wines under Stelvin (a screwcap closure), as this is the only way to ensure that the wine in the bottle is in the same condition as it was when the winemaker dispatched it from the cellar."

The cork debate does not end here. Time Magazine recently carried a feature article by Joel Stein under the title 'It's Getting All Screwed Up'. An extract is reproduced below:

'If only the whole point of drinking wine were not to impress people, screw tops would have taken off by now. Corks, many claim, are a great way to seal wine if you are a 15th century monk, but they are not so good today. Corks can crumble and allow air into a bottle, causing what is called corkage, a slight rotting of the wine. Some manufacturers have tried using plastic corks, but they do not always form a perfect seal and can impart their own flavour. So this year, many wineries are switching to screw tops - the same technology you find when opening a Colt 45. California's Bonny Doon, whose US$130 Cabernet opens with a flick of the wrist, threw a funeral for the cork in New York City in October, 2002. The cork industry is fighting back with a public relations campaign, but that won't stop vintners like New Zealand's Kim Crawford, whose bottles are all being switched to screw tops this year. There's nothing romantic about a corked bottle of wine, he says. Unfortunately, screw tops render obsolete the second snootiest aspect of wine: storing your bottles in a rack on their sides to keep the corks moist.'