Cork is made up of the outer tissue of the evergreen Quercus Suber cork trees, which are found only in certain areas of the western Mediterranean, including in North Africa, southern France, Italy, Spain and Portugal. Around the world cork oak grows over 2.5 million ha.
The largest area of cork oak forests are found in Portugal, which has also seen in recent years a systematic campaign of afforestation of wasteland with cork oaks. Portugal is the undisputed home of cork oak and the amount of cork they produce represents more than half of world production.
Cork harvesting is carried out in accordance with rules developed over the years. Removing the bark of trees is entrusted to only very experienced workers and the time of harvest is carefully chosen, taking the weather into account. The cork is impermeable to water and air. It protects the tree from water loss, the action of bacteria and micro-organisms, thermal fluctuations, as well as fires, which often occur in the areas where the trees grow.