As with wine containers, wine closures are an important choice that each winery must make, writes Gregory Dal Piaz from the USA. The effects of each closure go well beyond simply controlling the quality of the wine they restrain. There are also financial and ecological implications that accompany each selection.
Interestingly, what is ideal for one wine might be less appropriate for another, so it is worth keeping what type of wine (young and fresh, cellarable) we are talking about in mind when considering the pros and cons of each closure.
Crown Cap
Cheap and a nice solid seal at least for several years. Don’t believe it? Consider this, Champagne aging on the lees is capped with a crown cap until it is disgorged and fitted with a real cork.
It looks inexpensive because it is, but for many wines it’s all that is necessary, offering a good seal for those table wines you buy, bring home and drink immediately. In fact, one of the biggest drawbacks to the crown cap is that it takes a bit of effort, either a bottle opener or improvisation, to remove the cap from the bottle. Also, once it has been removed from the bottle, it is no longer a particularly useful closure.
Screw cap
The screw cap, or Stelvin, is fast becoming the standard replacement closure for most wine bottles. It is easy to remove, reusable, made of recyclable aluminum and can be fitted with gas permeable linings that allow for the same closure to be fitted to a variety of bottles.
The biggest drawback to screw caps, in particular the less expensive versions, is that an impact or mishandling can break the seal of the bottle.
Vino-Lok
Vino-Lok is essentially a glass stopper that fits snuggly into the neck of a wine bottle. I’ve had enthusiastic winemakers shake bottles upside down over my head in order to prove the tightness of the Vino-Lok, and color me convinced.
The Vino-Lok is predominantly made from recyclable glass, is fantastically reusable and is an elegant solution to the problem of a cork alternative. While this last point may seem trivial, the fact remains that many in the service industry prefer corks because of the presentation it allows them.
Synthetic cork
Synthetic corks come in a variety of styles, from solid rubber to composite corks that wrap a foam core in an elastic outer shell. This two-part product combines the best of both worlds, allowing for a controlled and consistent rate of oxygen transfer through the foam core, while keeping the exterior of the cork firmly in contact with the bottleneck.
Solid plastic or rubber corks, on the other hand, do not allow for oxygen transfer, and tend to fit very tightly in the neck of the bottle. This can make removal difficult and re-use impossible as sometimes you just can’t squeeze the cork back into the bottle. Another drawback with these solid plastic corks is the fact that they lose elasticity with time, allowing air to enter the bottle and degrading the quality of the wine.
In either case, while many of the products used for corks today can be recycled, these corks are generally produced from virgin resources, leading to a relatively large carbon footprint per closure.
Real cork
Real corks are the traditional closure for premium wines. Because the reasons behind that are many, it is difficult to remove this sentimental association from the marketplace. There is a lot working in favor of authentic cork closures continuing to be chosen as the closure for premium wines.
Chief among them is the simple fact that cork is a natural product that carries with it the lowest carbon footprint of any closure, in turn helping to support well-managed and ecologically important cork forests. The wine industry’s use of cork also helps to subsidize the cork materials made from scraps of bottle closure production, which has introduced cork to a number of industries which would otherwise not be served.
The downside of cork is and has remained TCA. That little molecule responsible for so-called ‘corked’ wines generally comes from infected corks, though dirty barrels and even hoses have also harbored TCA. The most prevalent cause of tainted wines continues to be cork closures. Whether that number is the 1% claimed by the cork board or the 10% anecdotal rate often mentioned by people in the business, it is a problem. Until the TCA problem is resolved, the door remains open for the whole gamut of alternative closures.
Composite cork
Composite corks or agglomerate corks are comprised of cork bits, plasticizers and adhesives. They combine some of the benefits of cork, while reducing the waste from traditional cork production. They also have some of the positive attributes of synthetics, and eliminate TCA through encapsulation of the cork bits.
Unfortunately, these types of cork, while consistently sized, are not consistent in their seal or gas transfer rates, making them suitable only for wines that are destined to be consumed shortly after bottling.
However, one specific producer, DIAM, has worked to produce corks with lifespans that extend out for 5 years or longer. While composites are still a work in progress, there is promise here for the cork lover.
(Source: SNOOTH)
Ends