I was having a discussion today with a well known former winemaker of a very well known Australian Wine Company, and we both agreed to disagree on the advantages and disadvantages of screw cap closures versus traditional cork.
The wine media and consequently the wine consumer in general have overwhelmingly accepted screw cap as the alternative closure and to some extent have gone overboard, where many distributors and marketers do not want to deal with wines that are still in cork.
There is such a wave toward screw cap, that even red wines that have been made to age are having difficulties if they are not in screw cap. The wine media have a lot to answer for, but also winemakers have embraced the concept of screwcap that prevents cork taint, and seal the bottle securely.
However it has also been argued that wines under screw cap can develop “burnt match” type characters and be overly sulphidic , a function of the fact that they do not breath as well as traditional cork. One of the major problems associated with cork, apart from cork taint, is random oxidation, caused by corks losing integrity.
However, the interesting observation that this particular winemaker made was quite intriguing. He was observing a bottling of Sauvignon Blanc under cork one day, and they had the vacuum filler turned up quite high, ensuring a strong vacuum was present inside the bottle once filled, to remove any air in the neck of the bottle. He noticed in a bottle after corking that an air bubble was trapped and slowly moving from the top of the bottle between the cork and glass, toward the wine, under vacuum. So essentially, the process they were employing to prevent oxidation of the wine, was in fact considerably increasing the risk.
It emphasises the fact that no matter how well in theory a process or system works during winemaking, it’s the implementation that makes the difference.
For the record, I’m ambivalent to the pros and cons of cork versus screw cap, and believe it is entirely up to the winemaker. Some styles certainly benefit from screwcap, and some certainly benefit from cork.
You can be sure though that this issue will polarize winemakers, marketers, and consumers alike for years to come, or at least until a new, cool, fad closure comes onto the market.