First let’s cover a couple basics about corks. Cork is a bark harvested from cork trees in the Mediterranean European countries, Portugal, Spain, Southern France, and Italy, some from the Gulf and Pacific areas of North America, Florida, Louisiana, Texas, Arizona, and California, and Pacific regions of China and India.
There are a few types of corks used for wines — straight cork, particle cork, and composite cork. Straight cork is all one solid piece of cork. Particle cork is a lot like particle board or ply wood, as in it is made from bonding small parts of cork together. Composite cork is a lot like sealing together saw dust, ultra-fine pieces of cork formed together. Then of course there are synthetic corks made from plastic.
Corks, regardless of type, all react very much the same for wine with some differences. Since cork is a plant it is naturally porous, and allows tiny amounts of air in over long periods of time allowing the wine to age in the bottle. While natural cork is the most porous, the other types will still allow for this aging just in a slightly longer time frame – while synthetic corks are almost total closures, mostly, but not completely, stopping the aging process.
Now for screw caps- this is technically called a Stelvin Closure. Screw caps create a complete seal through the use of the synthetic lining, so aging after bottling will not occur.
Depending on what the wine maker wants, he will use different styles of closures. Wines designed to age for long periods will use straight cork. Wines made to be drunk within 10 years may use any number of options. For wines made to be drank within 3 years, which is most wine on the market, a screw cap is the best way to go. Since it creates a complete seal, you don’t have to worry about the wine spoiling due to corks slipping during shipment or storage. Also, since organic closures run the risk of contamination during the growth or harvest time, they can eliminate that factor for potential damage. Let me note, cork taint, or something called corked wine, is a harmless bacteria in the natural cork. These bacteria will not harm the drinker in any way, but will make the wine taste and smell like an old dish clothe.
In short, screw caps are a good thing, depending on the wine. I know we all like to hear that authentic pop as we pull the cork out of a bottle, but considering the options, screw caps make sure the wine is fresher and tastes the way the wine maker wants. While the harvesting of cork has come a long way in the past 20 years, it is still not perfect. Don’t shy away from a bottle just because it doesn’t have a cork.
Dave Geurtze, Spa City Wine & Spirits