The truth behind the screw cap

In the early 2000s we began to see bottles with screw caps replacing those with corks on our off-licence and supermarket shelves. Much disappointment and debate ensued as wine enthusiasts mourned the ceremony, nostalgia and even the sound associated with popping a cork.

Some considered the screw cap a seal for only inferior or cheap bottles of wine, but today it is a method employed by many of the world’s top vineyards and even some Champagne producers, and has proved itself to be a successful technique for ageing wines.

The reason for this huge shift in manufacturing? Far more disappointing than losing a ‘pop’ to a simple ‘twist’ is the deflation – not to mention waste of money – felt when you open a bottle of carefully selected wine to serve to your dinner guests only to be hit with a nasty dose of taint or 2,4,6-trichloroanisole (TCA). In other words, your wine tastes ‘corked’, smells foul and is, quite frankly, undrinkable.

As the demand for cork has outstripped the supply – which comes from 6-9- year-old Cork Oak trees – an increasing amount of pesticides and wood preservatives were being used to prematurely age the trees. These TCA chemicals are sometimes still present in the cork and it is their reaction with the wine that is thought to cause the taint.

Screw caps have been found to have virtually no negative effects, keeping wine fresher and crisper for longer, whereas corks could affect up to 15 in every 100 bottles of wine sold. Plastic ‘corks’ were also introduced, however, have not caught on in the same way as screw caps due to the fact that they do not make a perfect seal and are a less eco-friendly alternative.

Although there are some concerns about the use of screw caps for the long-term ageing of wine, the method is generally gaining increasing support.