Alternative Wine Closures: The Evolution Continues

It was with a little scepticism that I opened a clean skin wine the other night that a friend had brought over. I had never seen the glass stopper closure released by Alcoa, even though it was released over 3 years ago, aptly named the “vino-lok”. It seems there is is growing acceptance of this alternative wine closure, at least within the wine industry itself, however I suspect that as with previous alternative closures, it will take a little longer for the general wine consuming public to accept.

On their website Alcoa describe the “Vino-Lok as follows:

“The Vino-Lok system is based on the idea of providing the bottle with a stopper that is 100% neutral both in technical terms and from the standpoint of a wine connoisseur. At the same time, on an esthetic level, it offers the consumer what he or she expects in a stopper for a good bottle of wine. Vino-Lok provides the highest level of product safety and taste neutrality without the risks and drawbacks of a cork. Besides that, the stopper is completely recyclable.”

After opening the wine with the Vino-Lok system, I was suprised at the familiar physical action required to pull a cork. Of course the main purpose of this closure, as with all alternative closures, is to remove any chance of cork taint. Cork taint is common amongst all wines with cork closures.

The chemical that causes the taint, TCA, is a by-product of chemicals used in the cork plantations around the world, and the taint produced ranges from a faint musty character in the wine, to absolutely offensive odours. The biggest challenge facing winemakers is that many consumers who are limited in their knowledge of cork taint, perceive the wine to be just plain awful, when in fact the offensive character is caused by cork taint.

Many alternative closures have been trialled over the last 20 years. Some have been very successful, such as the screw cap, that has now been accepted as the norm by most new world wineries and consumers, albeit after a considerable lag period of acceptance. Not so successful is the synthetic or plastic cork. While it mimics the look, size, shape and feel of real cork, as well as producing the traditional “pop” sound when opening the bottle, it has been plagued by it’s own taint problems and has all but disappeared from the market.

As with all alternative closures, none have yet to mimic the cork in all its natural glory, and that is the “breathing” effect cork allows over the lifetime of a wine in bottle. A key process in the maturation and aging of wine is the permeability of the cork to allow air to flow in and out of the bottle at incredibly low rates. There is of course some conjecture as to the importance of this in the aging process, and much of the research itself has been conducted by the alternative closure manufacturers themselves.

As a side note, natural cork closure manufacturers do offer a range of quality at different price levels for wine makers, presumably the higher quality corks have the lowest chance of causing taint or leakage. However an interesting economic influence has meant this is not alway true. A few years ago I was talking to a well known Australian wine maker who had just purchased the highest quality cork for a small batch of signature series of wines he was producing, and the cost was significantly more compared to the normal quality cork.

After trials in his lab, luckily prior to using the high quality cork as a closure, he found that the incidence of taint was actually much larger than his normal batch of corks. After further investigation, he found that the cork he had purchased had been sitting in the warehouse in Australia for a number of years as only a limited number of wine makers ever purchased the higher quality expensive corks. Therefore he surmised that the corks had lost there integrity and any taint present was amplified.

If you ask any wine consumer, and any purist wine maker, they will almost all tell you that if they had the choice, they would choose natural cork over alternative closures if the taint problem could be fixed. I find it interesting that it’s actually a man made problem, and after all these years, it has still not been resolved.

2 thoughts on “Alternative Wine Closures: The Evolution Continues”

  1. Jono
    A few points in relation to your article: 1. Cork taint is not “common amongst all wines with cork closures”. The incidence of cork-related taint in wine has fallen significantly in recent years as cork manufacturers improve their production processes. Recent results from major international wine shows suggest the incidence is about 1%. 2. Chemicals have not been used in cork forests for many years. 3. TCA is a contaminant that occurs when natural microorganisms meet chlorophenol compounds and convert them to chloroanisoles. TCA affects many food and beverage products and is even found in bottled water.

    • Even 1% of wine tainted would seem quite common given the many millions of bottles of wine produced and purchased world wide each year.

      I am reasonably certain, however, that the incidence of cork tainted bottles is more than 1 in 100: though this is also anecdotal.

      One must also consider that the wines at international wine shows are likely to be using cork of the highest quality, too, so any patterns based upon these top-end wines must surely be regarded with a degree of circumspection.


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