Pulling all the stops out...

Screwcap, plastic or cork - the debate over how best to stop wine rages on. Ben McFarland raises a glass or two and weighs up the pros and cons.

Two, four, six trichloroanisole doesn't exactly roll of the tongue, but it does leave a rather nasty taste in the mouth.

TCA, to give it its abbreviated name, is the naturally occurring chemical that resides mostly in cork found at the bottom of a cork tree. It is TCA that wheedles its way into a bottle of plonk and renders it "corked".

A corked wine is not, as many people mistakenly assume, a result of a badly opened bottle that has fragments of cork floating in the wine, but rather a wine that gives off an unpleasant musty scent.

George Samios, the wine communication manager for Beringer Blass Wine Estates in Australia equates the smell, in severe cases, to "a musty cellar, wet carpet, wet Hessian sacks or a wet towel".

He adds: "A corked wine has off characters as the result of using a cork that has been affected by the action of mould combined with traces of chloride compounds from the environment. It's not a pleasant aroma.

"In more mild cases, the taint will make a wine smell flat and devoid of the normal bouquet one would expect, especially from say a young fresh riesling or sauvignon blanc. Often the wine will also appear flat on the palate, and in some cases it is only on the palate where this taint can be detected."

Following its survey conducted last summer, the Wine and Spirits Association (WSA) set a "benchmark figure" for the number of bottles of wine in the UK affected by "commercially significant levels of mustiness". The WSA estimate of between 0.7 per cent and 1.2 per cent, however, has been widely challenged by proponents of alternatives to cork.

Villa Maria, a winery in New Zealand that has replaced cork closure with screwcaps on all its wines from the 2002 vintage onwards, claims that up to eight to 10 per cent of all wine with a cork closure can be tainted and a further 30 to 40 per cent can be dulled or oxidised by imperfect corks.

George Fistonich, Villa Maria's owner and managing director, said: "It's really an old-fashioned technology - the medical profession gave up cork three or four decades ago, spirits used to be bottled in cork, they've given that up. It's stayed in the wine industry because of this romantic tradition - basically it's like driving a Mercedes sports car with wooden wheels - obviously you don't."

Carlos de Jesu, marketing and communications director for Amorim, a leading Portugese cork producer, prefers a different analogy.

"It's more like driving a Mercedes with luxurious wood panelling," he said. "We sell more than three million corks a year and there's not one quality wine that doesn't have a natural cork stopper.

"With the new processes that we have put in place in the last couple of years we have reduced the cases of TCA by 75 to 80 per cent and that figure has been independently validated.

"Natural cork has been falsely made a scapegoat for a lot of things ranging from oxidisation, poor wine making techniques and microbiology. With wine, there's no such thing as a perfect stopper but there are clear technical and ecological reasons to use natural cork."

While the vast majority of wines are sticking with cork, New Zealand winemakers, renowned for their early drinking wines, are spearheading the move towards screwcap and it is predicted that around 20 per cent of wine produced in the country will be bottled under screwcap by the end of the year.

In the UK, screwcaps (or Stelvin closure to give it its branded trade title) have long been associated with unfashionable wines such as Leibfräulmilch and Lambrusco and it is for this reason that more brands have refrained from closing their bottles with a twist rather than a "pop".

The wine industry has been aware for years that a screwcap is the best bet as a reliable closure, but until now, it has lacked the courage to act upon its findings.

However, with the supermarket money men and drinkers becoming increasingly intolerant of the "romantic" inconsistencies of traditional cork, a number of major brands have made the switch - primarily on younger, fresher and early drinking wines.

Jacob's Creek, the UK on-trade's leading Australian wine, has introduced a screwcap for its riesling while other brands such as Lindemans, Penfolds, Rosemount and Hardys have all swapped a cork for a cap in a number of off-trade accounts.

Jacob's Creek master of wine Peter Carr said: "Having seen a couple of sommeliers trying to open a screwcap with a waiter's friend it is a question of identification and education. There are also some environmental issues with the waste metal that will have to be taken into account.

"However, according to the sales in some of the supermarket chains consumers are ready for screwcaps.

"Many of the products offered have been heavily promoted which may account for some of the success.

"But I would suggest that it is too early to tell and some research we carried out as part of a response to new labels indicated that there were still some negative perceptions to overcome.

"From our own research, the case for synthetic closures has not yet been proven and with the quality control we carry out in our cork purchasing we will continue to monitor trade and, more importantly, consumer reaction to screwcap on other products before extending it in the Jacob's Creek range."

E&J Gallo, a brand poised to make on-trade inroads courtesy of a high-profile link-up with Waverley Wine and Spirits, has also test-marketed its Turning Leaf brand but the winemaker insists it has no future plans to convert the rest of the range.

Last year Tesco launched "Unwind", a range of own-brand screwcap wines. Helen McGinn, product development manager for Tesco Wines, said: "We wanted to move to screwcaps for quality reasons and challenge the idea that they were associated with cheaper wines.

"We are now selling between 600,000 and 1.5 million screwcap wines a month and in all cases sales have increased when a wine converts from cork to screwcap."

While those who drink a bottle of chardonnay or merlot at home may be willing to experiment, it seems that pub-goers are not so adventurous.

Mark Dally, wine and purchasing director at London brewer Fuller's, said: "It's a lot harder to get screwcaps accepted in pubs than it is the off-trade. I think wine is more traditional in the on-trade and there's an issue of theatre and opening a bottle at the table.

"It's purely image and although perceptions will have to change, at the moment too many people would be unhappy about it."

A similar level of prejudice threatened to scupper the emergence of the plastic cork in recent years, but synthetic alternatives are now widely accepted.

As well as plastic, synthetic closures come in various guises including agglomerate corks, made by binding smaller pieces of cork together with an adhesive to form a single closure, and colmated corks which are tree bark cork whose cracks and holes are filled with a combination of cork dust and adhesive.

Around one in three wines sold in the UK, especially at the competitively priced end of the market, is sealed using a synthetic closure and it is generally regarded as more consistent than natural cork yet more acceptable among drinkers than a screwcap.

However, critics of plastic closure claim that plastic does not entirely remove the risk of taint as the bottles are not always airtight.

Critics also claim that a plastic smell can sometimes be detected and that the synthetic cork has yet to prove itself as a suitable closure for wines that require ageing.

"In a pub, the plastic cork is not great because you simply can't open it easily," added Mark Dally. "The bar mounted corkscrews just pushes the plastic cork into the bottle and covers the barstaff