by Carolyn Prusa CWE
The Evolution Of The Screw Cap
I still vividly recall the occasion, although it was years ago (30? Could it really be?), when a business client presented me with a holiday gift - a bottle of wine with a cork closure. Until then, because of my limited exposure to wine - not to mention my limited bank account - I was always attracted to the jug wine section of the store.
That gift bottle with the cork? It was - don't laugh - Blue Nun Liebframilch. (Those of us who don't grow up in wine drinking families have to start somewhere.)
I liked it. The light, fresh flavor of that non-pretentious German white 
wine was quite superior to what I'd been buying (I'll never tell). With that, I swore off wines with screw caps, broke into my piggy bank for a serviceable corkscrew and some wine books, and begin educating myself with slightly more spendy wines. It was the beginning of my long and wonderful relationship with wine.
And, I stuck to my pledge of no more screw caps. Until a few years ago, that is.
If you've spent much time in the wine stores recently, I'm sure you've noticed all the wine bottles with screw caps - and not just the el cheap-o blends. Yes indeed, premium winemakers around the world are forgoing corks in favor of twistoff closures.
Sealing fine wine with a screw cap is a trend gaining ground, and the relative upstarts in New Zealand have been leading the way. Eight or so years back a daring group of over 25 down-under wineries began using screw cap closures on their more expensive wines. After a favorable response among consumers, the practice grew. The twist-offs now have converts in the U.S., Australia, Europe, South Africa, South America, and Canada.
It's common for wineries to use 100 percent natural cork for their flagship wines and the screw cap for wines that are to be consumed within a few years. One of the more sophisticated versions of the twist-off cap, and the closure of choice for many wine producers, is the Stelvin, which has a liner specifically designed for contact with wine.
What's behind this shift from cork to cap? The answer is 'cork taint' which leaves the wine tasting musty and dull.
It's estimated that approximately 17 billion corks are used every year, and by some estimates, at least one bottle in twelve is 'corked' - in other words, tainted - resulting in a worldwide loss to producers of up to $10 billion a year.
The dank, moldy smell and taste in 'corked' wine comes from trichloroanisole (TCA ), a compound formed when chlorine used for bleaching reacts with mould already growing in the cork. TCA can be present in areas of a bottling facility, such as drains and barrels. But according to various studies, the wine cork itself is the biggest culprit. Any wine can become 'corked', inexpensive ones that are opened and consumed the day they are bought or rare collectibles.
Proponents of screw cap closures say that as long as makers of fine wine continue to rely on 17th century technology for 21st century wines - referring to corks, of course - the problem will continue to exist. Those in favor of natural cork closures, as you might guess, insist that cork taint is greatly exaggerated.
So, don't throw away your corkscrews just yet. Natural cork closures have a centuries-long heritage that isn't about to disappear from the face of the earth any time soon. There will always be wineries that choose to stick with tradition no matter what, never switching from cork to alternative closures.
Can't say I blame them, although I was surprised to discover how much a good natural wine cork costs. According
to a June 2007 report in Wine Business Monthly, at least one high profile California winemaker was reportedly paying $0.80-$0.90 per cork.
It's little wonder wine corks are pricey considering that cork oak trees are 30-40 years old before they are harvested for the first time. Besides which, the first harvest cannot be used for wine corks! Manufacturers of wine corks must wait another ten years for the next harvest, then every ten years after that. The good news is, cork oak trees, which grow mostly at the southern end of Portugal, Spain and northern Africa, can live for hundreds of years.
Cork manufacturers are taking a very aggressive stance against cork taint, as you would expect. They are also developing more advanced techniques for the detection of the taint that causes wine to become corked in the first place. But they're now up against a lot more competition than ever before.
Another alternative bottle closure in use is the synthetic cork. Derived from plastic, some resemble real corks while others are any bright color of the rainbow depending on the winery's choosing. I'm no fan of these cork wannabes. I've found that a lot of them are very difficult to remove and often impossible to shove back into the bottle.
Back to the screw cap. Besides eliminating cork taint, another upside of the twist-off closure is convenience. Opening the bottle requires no special tools or strength to open, and it's easier to reseal. The bottle with the twist-off cap can be stored in any position, while the unopened bottle with a cork closure should be stored on its side or upside down to keep the cork from drying out.
US producers such as Ferrari-Carano, Benton Lane and Beringer (to name a few), Wolf Blass, Annies Lane and Penfolds Koonunga Hills in Australia, Cloudy Bay and Matua Valley in New Zealand, Schloss Schonborn in Germany, and Veramonte in Chile are just some high-profile examples of the world's many wine producers utilizing the twist-off cap for some of their wines.
What can I say? Years after graduating from screw caps, I seem to have come full circle. As I write this, the stock market and the economy are on the downslide, and I'm once again searching for the real wine bargains. Looking on the bright side, because wine quality around the world has improved immensely over the last thirty years, I'm finding there are plenty of good-value wines to be had (you'll hear from me later on that subject).