Debate rages currently over the merits and pitfalls of various wine closures. Cork has the longest tradition of usage and the best examples are considered a very good option for long-term wine storage. Cork, at its best and free from taint will allow a wine to age gracefully for up to 25 years. Unfortunately, not all corks are alike, some will fail earlier than this time. The application process can also sometimes result in damage to the external surface of the cork, causing very slow leakage and/or quicker oxidation of the wine. This is particularly upsetting if you like to drink your wines with a little age on them. The longer you age, the higher the chances that some of your ‘rainy day’ wines will be affected by random bottle oxidation.
It is a popular myth that cork allows a slow, flavour positive exchange between wine and oxygen. Cork is chosen for its ability to prevent additional oxygen from affecting wine once in bottle. Wine in bottle will contain a very small amount of oxygen trapped in solution. It is a commonly held misconception that oxygen in bottle is the greatest contributor to the creation of mature wine characters. Wine maturation is essentially anerobic - i.e. it occurs in the absence of oxygen. Unfortunately cork, whilst having excellent sealing properties for a naturally occurring substance is notoriously variable. Stelvin caps are a far more reliable means of preventing the ingress of oxygen into wine.
Trichloroanisol (TCA), a.k.a. cork taint also plays a role in altering the flavour profile of wine, affecting up to 20 percent of all wines. Cork taint in its most extreme expression, will kill a wine's fruit flavours and aromas, replacing them with a wet hessian, or undried washing character. Sadly, in lower concentrations it can simply dull fruit character, drastically reducing your enjoyment of the wine. This level of taint is particularly disturbing for wineries, who are often blamed for producing average wine, where in fact the closure may be the real culprit. Unfortunately it is a very time consuming and expensive exercise to isolate affected cork batches prior to bottling.
The most widely accepted alternative closure is the Stelvin (a type of ROTE - Roll on tamper evident) cap, or Screwcap. Detractors have suggested that wines under this closure do not age. This is not so. Wines under Stelvin do age, typically more slowly and more uniformly than wines bottled under cork. This may be of minor frustration to some, but it makes predicting when best to drink a wine a far more exact science. If you open a bottle and it tastes a little young, then the rest of your case will need further cellaring. If it tastes spot on, then you’d best start drinking them. Typically though, you need not rush, Stelvin affords you plenty of breathing room…
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