Anyone who knows me will already know that I tend to turn my wine snob's nose up at bottles with plastic corks or screw-cap closures. This distaste is has two sources.
1/ As any wine lover will tell you, wine breathes, ages and evolves better in a cork closed bottle. Why is this so? Well, for a wine to continue to mature once it's been bottled, there must be a continuing exchange between the wine in the bottle and the air surrounding the bottle (if you're lucky, this will be the cool and relatively humidity-stable air of a good cave). Plastic corks and screw-caps hermetically seal the wine meaning it cannot age. This is fine if the wine is intended for consumption within... max 2 years after bottling, but it is equivalent to suffocating a Saint Estèphe or a Vosne Romanée.
2/ Environmental issues. A plastic cork is just downright bad for the environment. It's made from petro-chemicals. It doesn't biodegrade and probably most plastic corks end up in the household rubbish bin with no hope of being recycled.
A traditional cork, however, is good from beginning to end. Natural cork is harvested from cork oaks (Quercus suber), with the largest production areas to be found in Spain and Portugal. The cork oak forests are ancient mixed-farming areas, combining forest and grazing pasture. Because the harvesting of the bark is done using traditional methods and involves no mechanical techniques, the habitat is preserved. Animals such as the endangered Iberian lynx and Spanish eagle rely on these forests and suffer from their conversion to intensively-farmed agricultural land.
To help preserve these essential habitats, and ensure a future for cork oak farmers in Europe and elsewhere around the Mediterranean, you can make a difference by choosing to buy wine with a natural cork stopper and steering clear of plastic and screw-caps. Some UK retailers are now indicating the type of closure used on their wines either in their online catalogues or in store. But they are also applying pressure to their wholesalers and suppliers to provide wine with plastic or screw-cap closures. You can help by just not buying these wines, writing to the supermarkets and retailers, and writing directly to suppliers to give your views. Consumer pressure does make a difference.
And the biggest thing you can do to help is boycott all wine from Morrison's. Or better still, boycott their stores altogether. This is because Liz Robertson, former head of wine for Safeway (now Morrison's), is stupid. She said "We think that plastic stoppers are good for the environment because they relieve pressure on the cork groves and prevent over-harvesting.” Clearly, she has NO IDEA at all. Cork oak farming is probably the only form of farming in Europe today that doesn't involve over-harvesting. And yes, something made from hydrocarbons and that doesn't biodegrade and isn't recycled is obviously good for the environment. Of course.
Some links to find out more:
Real Cork campaign
Environmental news service article
WWF Mediterranean Cork Oak conservation project