Screw Cap or Cork?

Screw caps were originally equated with only being used for cheap, ordinary tasting wines - and some people would argue that this image has still not yet been fully shed. But as the US begins experimenting with screw caps on select wines, and with leading wine industry New Zealand converting 25 wineries to use caps, alongside acclaimed wineries in Australia, South America, South Africa, France and Canada, it looks like the trend for and image of screw caps could be changing.

To give you a better insight into how each sealer works we have provided you with a brief overview of each function below.

Natural cork: These closures have been around for centuries. In fact, they have been used since the 17th century when champagne maker Dom Perignon began making the famed nectar. Natural cork gains its appeal in its elegance and tradition.

However, once a bottle is corked, the bottle will take on a musty smell and taste that arises from TCA (2,4,6 - Trichloroanisole) in cork. This substance is used to sanitise the natural cork before wine is bottled but unfortunately it produces am unfavourable flat flavour and it's estimated that about five to 10 per cent of wines on the market are 'corked'.

The other issue with natural cork is that with so many billions of wine being produced each year, it's becoming harder to make sure enough cork trees are being produced.

Synthetic cork: Synthetic cork is derived is made from plastic and appears to be a good alternative to traditional corks. Synthetic cork can prevent the wine from being tainted from the TCA that is present in natural cork. The other appealing factor of synthetic wine stoppers is that they can be made to any colour or mould. Synthetic corks will also not disintegrate or dry out.

But because synthetic corks are unable to prevent oxidation, synthetic corks decrease the shelf life of wine. Some wine connoisseurs believe that air is needed to help the wine mature so because synthetic corks completely blocks air out of the bottle, synthetic corks may short-change the maturing process of select wines.

The other debate is that is that while synthetic corks can be recycled, if they aren't they could become a threat to the environment.

Screw caps: Screw caps provide the best seal for bottled wines because they eliminate both the 'corked' and the oxidation problem. Washington-based Hogue Cellars completed a 30-month study that compared natural and synthetic cork closures with popular screw cap type, Stelvin. The results of the study suggest benefits for using screw caps over natural or synthetic cork functions. It showed that screw caps allowed the lowest amount of oxygen permeation in comparison to natural and synthetic corks, protecting oxidation of wine.

One of the downfalls of screw caps is that they do take the romance and drama of opening a bottle of wine or champagne. According to wine expert and internationally known wine writer Jancis Robinson, the disadvantage of screw caps is that they may suppress a wine's aroma, possibly causing an unpleasant smell. However they do ensure that the wine's flavour is not tainted by cork, that it retains freshness, and consistently ages.

What to Choose

Natural cork, synthetic cork or screw caps. With a fair balance of pros and cons for each wine bottle stopper, everyone will have their own opinion about the matter, but screw caps have proved enough benefits to overcome its initial stigma, to be favoured more and more by the wine industry today.