Where do corks come from?
The cork used to seal your wine is a piece of bark. It is taken from the cork oak, a medium-sized evergreen oak tree otherwise known as Quercus Suber. It is native to southern Europe and northern Africa, and you will find the trees growing in large areas of central Portugal, Spain and northern Morocco.
It takes 25 years for the tree to reach maturity, and only then can strips of thick bark be harvested every 10 years or so without damaging the tree. Some cork oak trees can be 100 years old, and even more. In Portugal and Spain Iberico pigs shelter under the trees and feed on the acorns.
The bark is taken to a factory, where it is dried for several months before being immersed in boiling water. Then the outer bark is stripped away and the corks are punched out of the bark. Bark that is not thick enough is used to make less expensive corks such as technical corks, made from slices or disks of cork, or agglomerate corks, made by gluing tiny bits of cork together. The best corks are expensive, and can add more than €1 to the price of a bottle of wine.
In the past, corks were often treated with unclean water, and some became infected with TCA (2,4,6-trichloroanisole), leading to “cork taint”, giving the wine a nasty off-flavour often described as dirty dish cloths. These days great care is taken to avoid this and the incidence of “corked” wines has dropped.
Most cork is destined to become a stopper for wine, but it is also used to make tiles, sandals and flotation devices.
