Screw caps have been associated with cheap wines in the past and have had some serious perception hurdles to hop; however, they are definitely on the rise with many winemakers in the U.S. and abroad experimenting with them on select wines. New Zealand is leading the wine industry with the majority of wineries converting from cork to cap. Wineries in Australia, Spain, South Africa, South America, Canada, the U.S.

And France are all testing the capping trend as well.

Currently there are three ways to close a bottle of wine: natural cork, synthetic cork and screw caps.

Natural cork closures have a centuries-long heritage; however, they allow for a bottle of wine to be “corked” as the saying goes. A “corked” bottle has a musty smell and taste that stems from TCA (2, 4, 6-Trichloroanisole) – a substance that is formed when chlorine-based sanitizing agents come into contact with naturally occurring fungus on the cork.

When bleach and other chlorides are used to sanitize the natural cork prior to bottling the chances of TCA contamination increase significantly. The result is a flat, moldy flavor devoid of fruit-filled taste and aroma. It is estimated that about 5-10% of wines available on merchants’ shelves are “corked.”

Synthetic corks, derived from plastic, appeared to be a viable alternative to traditional corks. However, their track record has been tarnished due to their inability to keep oxidation at bay for any real length of time, significantly decreasing the shelf life of a wine and short-changing the maturing process of select wines.

Screw caps provide the best seal for bottled wines, and eliminate the “corked” and oxidation problem in one fell swoop.

Hogue Cellars completed a 30-month study comparing natural and synthetic cork closures with the Stelvin screw caps, their findings suggest significant benefits in utilizing screw caps over either natural or synthetic cork closures. While, screw caps do diminish the drama and romance of bottle opening it is well worth the sacrifice to ensure a taint-free wine that offers consistent aging, maintained flavor and freshness with optimum quality control.

The Stelvin screw cap appears to be the industry’s cap closure of choice. Many mainstream producers are embracing the screw cap closures for wines at variety of price points. Though white wines are the obvious first step for the capped closure system, many red wine producers are opting for the same to maintain freshness and clamp down on cork taint. Screw cap concerns still exist for wines that are made to age. Further research is needed to determine if wines that are built to go the distance of a decade or more can opt for cap over cork without interfering with the aging process that often relies on small oxidizing elements.
By Stacy Slinkard

Wine Expert

***Grabbed from: http://wine.about.com/od/storingwines/a/Screwcaps.htm