With its light-weight honeycomb structure, impermeability to liquids and gas, and its flexible membrane, cork is the ideal material for products ranging from stoppers to floats, from flooring tiles to gasket material, from clothing to coasters. There is no other material, either natural or manmade, with all of the characteristics that are unique to cork: light weight, rot resistant, compression and expansion, fire resistant, impermeable, soft, and buoyant.

The cork oak is an evergreen tree, known as Quercus suber. It grows in the sunny south of Portugal, Spain, and North Africa (Morocco, Algeria, Tunisia) however, Portugal accounts for more than 50% of the world's total cork production. It is the climate and soil types of these regions that keep the trees growing. Although cork trees are also grown in some Asian countries, only cork harvested from the Mediterranean region is of a quality good enough to be commercially viable.

This remarkable tree has a bark which is unique throughout the plant kingdom. The cork bark can be 'stripped' off allowing new bark to grow in its place. This makes every tree a source of raw material. Every part of the cork oak is useful for a variety of purposes:

· Leaves - for animal fodder, natural fertiliser

· Fruit (acorns) - for animal fodder, cooking oils and ground animal feed.

· Trunk - for firewood and charcoal, paper paste, chemical products (tannin, acids), boat building.

· Bark - the main reason for cultivating the cork oak and used for wine corks and other cork products.

Harvesting Cork Bark

A cork tree has to be at least 25 years old before the bark is harvested for the first time. Cork from the first harvest (Virgin) and the second harvest (Secondary) cannot be used to make wine corks but are used for other products. Only at the third harvest, when the tree is 43 years old, is the bark smooth and regular enough for the production of wine corks.

By law a cork tree may only be harvested once every nine years. On average, each cork tree is harvested 15 -18 times in its lifetime. The harvest takes place in the northern hemispheres warmer months between June and September. The tree is growing at this time, which means that the bark can be easily removed from the trunk and a new outer skin grows quickly. Stripping the outer bark is a very delicate operation carried out by skilled workers using special axes.