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Cork closures debate rages on

Producers are still at odds as to which style of closures are best for their wine, writes SUSIE BARRIE.

What do you think of laminate flooring? Trendy, minimal, or, if you’re like me, pointless – it’s just not the same when it’s not real? Why saddle yourself with the downsides of wooden floors – the cold, the noise and the dust – without at least the pleasure of beautiful solid wood? I tend to have the same attitude towards synthetic closures. To carry the analogy further, laminate flooring warps quickly, just as synthetic corks expand when removed, seemingly never to fit again. Then again, how do you feel when you buy a beautiful, rose-hued mango from the supermarket, which gives to the touch, suggesting perfect ripeness? You take it home and slice it only to find that the juicy, sweet flesh you’d anticipated is stringy, tasteless and fit only for the bin? Feelings of frustration inevitably follow. Why can’t the producer work harder to give his fruit the best care and attention in order to offer 100% quality every time? Open a bottle of your favourite wine only to find that the natural cork closure has tainted (with the chemical TCA) the delicious liquid inside, and you can see the case for synthetic.

Taking sides

The heated debate concerning the use of ‘synthetic’ versus ‘natural’ corks – not to mention the fairly recent arrival of the Stelvin screwcap for quality wines – is not new to the wine world, but the cork industry has only fairly recently decided to fight its corner in a concerted fashion, putting its money where its mouth is.

APCOR, the Portuguese Cork Association, has decided it’s time to sit up and take notice of the threat posed by alternative closures, and has ploughed money into a high-profile awareness campaign. Portugal is the world’s largest producer and exporter of cork in the world with a 54% share of the market. APCOR’s 250 members account for around 75% of the total national production and 80% of all cork exports. Fifteen billion natural cork stoppers are produced every year.

In January APCOR launched the Cork Information Bureau, with a budget from the government and its members of t8million. ‘We felt it was time for the cork industry to communicate through a united voice and for us to raise awareness of the consumer preference for natural cork,’ says Francisco Evangelista, director of APCOR’s International Campaign for Cork. The organisation recently published a report suggesting that 75% of us prefer natural cork stoppers and 26% think that the most important factor when choosing a bottle of wine is its type of closure – ahead of the brand name (21%) and the price (22%). However, the report does go on to say that over half of us would like the type of stopper to be stated on the label – rare at the moment.

Attitudes change as you cross borders, too. 83% of those questioned in the USA and 79% in Australia see cork as a sign of quality, while in the UK the figure is only 43%. There has been no fall in the demand for natural corks since the introduction of synthetic closures in the early 1990s but, as Evangelista admits, ‘we do know that the market for closures is increasing so we can assume that our market share is lower.’ The problem for cork producers is that nobody knows for sure what causes TCA to occur – this is the chemical compound which renders a wine ‘corked’ – or at what stage in the process of producing a cork it develops. As Evangelista says, ‘in all the different phases of production there is room to improve’.


TCA is believed to be connected to chlorine and the reaction of this with the natural cork bark – depending on who you listen to, the problem affects anything from 0.6% to as much as 7% of all wine. The boiling procedure traditionally used to clean the wood is now thought to be inadequate and companies are trying new approaches such as keeping the boiling water in constant circulation and filtering it so that contaminants are quickly flushed through the system. Another solution is to use steam; this allows more vapourising of contaminants. A laboratory methodology that is commercially viable as a quality control tool is one of the main things that the Cork Quality Council is trying to establish.

Although the money invested in the Cork Information Bureau is going largely towards advertising, marketing, PR and online activities, Evangelista is quick to point out that the money is also being used to improve communication with the producers themselves, to make them more aware of the changes and improvements that they can, as an industry, implement. ‘There was a lack of communication in the past, and we believe that this has hurt us as an industry. We acknowledge the problems we need to address, and changes are happening as we speak.’


The other side of cork closures

In 1992 SupremeCorq, the world’s largest producer of synthetic closures, launched its version of the alternative ‘cork’. According to SupremeCorq, a massive 750 million synthetic closures are produced annually, by SupremeCorq and other brands including Aegis, Auscork, NuKorc, Normacorc and Neocork. The last on the list is unusual in that its investors are all big wineries (Beringer, Kendall-Jackson, Sebastiani, Mondavi and Allied-Domecq) rather than businesses from the usual ‘injection moulded plastics’ background. Although all these products differ according to their scientific make-up, one of the criticisms generally levelled against this type of synthetic closure is that wines stoppered in this way can age prematurely, making the closures suitable only for fresh, fruity wines which are intended to be drunk young.

Another common criticism is that they can often be difficult to extract from the bottle and – should you ever find yourself needing to perform this task – to push back in. The suggestion previously made by some that the plastic somehow taints the wine seems to be one that most people agree is unfounded. SupremeCorq has recently launched the new Preserva range, ‘engineered to allow wines to age longer in the bottle’, and although it’s very early days it claims that, to date, free sulphur dioxide levels (a good guide to the freshness and condition of a wine) have been retained at the same rate as a high-grade tree bark cork. In SupremeCorq’s most recent consumer survey (carried out in 2000), 92% of respondents rated synthetic closures ‘as good as natural cork’ or ‘better than natural cork’. In addition, 67% said they actually ‘preferred’ or were ‘indifferent to’ synthetic closures.

Findings from Oz

An invaluable and impartial addition to the material available comes from the Australian Wine and Research Institute (AWRI) Wine Bottle Closure Trial, a study whose preliminary findings were published last summer after an initial 20-month study period. The 41-page document contains some interesting findings. The best performing stopper when it comes to keeping a wine fresh is the ROTE (roll-on tamper evident), or screwcap; four of the 14 bottles stoppered with natural cork (two different quality levels were used) were tainted with TCA; and no plastic-type taint was associated with any of the synthetic closures tested.

As yet, it’s too early to say whether the plastic stoppers will cause the wines to age more quickly than they would do under natural cork, but there is enough wine cellared to enable the study to continue for a decade.

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