Cork vs. Screw Cap
There are a lot of assumptions made about wine when it comes to screw caps versus corks – and not all of them are accurate.
Natural cork closures have a centuries-long heritage, but after hundreds of years of tradition, more and more winemakers are turning away from cork in favour of screw caps. But because screw caps were for years associated with cheaper wines, winemakers are working very hard to overcome these perceptions in the name of progress.
So what’s the issue with corks? There are a couple of culprits: air and a nasty little chemical compound called TCA (or 2, 4, 6-Trichloroanisole).
Natural corks are made from the bark of cork trees grown in Spain and Portugal. TCA is a chemical compound that is used to sanitize the natural cork before bottling. However, remnants of the compound can often remain in the corks. Some say up to 5 to 10 percent of corks will have TCA in them. The issue with TCA is that is can cause a wine to become corked. A corked wine has a flat, moldy flavour that lacks the fruit-filled taste and aroma normally enjoyed in a wine, and generally announces itself with a moldy cardboard smell upon opening.
The other culprit at work with natural corks is air. Winemakers battle endlessly with air. Their job is to protect their wine from too much exposure to air, which is what causes oxidization. That’s why wine bottles are filled nearly to the very top and then sealed. The little bit of air left, or contained in the cork itself, then helps the wine to age. The problem comes in the variation found in natural cork. One cork might be 1,000 times more porous than another cork, which means vast differences in how bottles of the exact same vintage will age.
This is why more and more modern winemakers are embracing the screw cap as an alternative to cork closures. They provide an airtight seal and eliminate both the corked and oxidization problem in one step. They might be a touch less romantic or dramatic to open, but wine enthusiasts generally like their offer of consistent aging, as well as the maintenance of both flavour and freshness.
So whether you choose to purchase wine with a cork or screw cap closure, it’s best to pay closer attention to the wine label rather than the wine closure because cap versus cork is no longer a sign of the wine’s quality or heritage.