The cork industry in Portugal remains to be one of its most important exports representing about 16% of total foreign income and employing some 20,000 people. The cork oak (Quercus suber L.) covers approximately 8% of the total area of Portugal, 5.3 million acres, is in Portugal, and produces nearly half the cork harvested annually in the world (about 310,000 tons).
The forests are protected by law and the felling of the oaks is not permitted except for thinning or removing old and unproductive trees. The cork oak is extremely versatile with an enormous capacity for regeneration. It can live from 150 to 200 years, with the bark being stripped at nine-year intervals during its lifetime. Following harvest, which is still done using the same methods since its qualities were first recognized, the bark is seasoned. Seasoning enables the cork to develop a uniform level of moisture and stabilize. No more than 50% of the bark is removed during harvest, allowing the tree to protect itself using its own natural defenses. The bark is practically impervious to liquid and gaseous substances, extremely light and flexible, it is also incombustible, an excellent insulator and is extremely friction resistant. Equally important in today’s society however is that it is totally natural, recyclable and biodegradable.
Throughout history cork has been utilized as a commodity and references are found of its use in fishing tackle as far back as 3000BC, it really developed however at the same time as the development of glass bottles when, in the second half of the seventeenth century, a French monk named Perignon disovered its special qualities and a new era began for Quercus suber, with the need for suitable stoppers for wine. The natural cork stopper became the norm for an ever expanding wine industry, with the two products having enjoyed a symbiotic relationship for many years. Although the intervention of the plastic cork had a detrimental effect, the material and its industry, first written about in the 4th Century BC by the Greek philosopher Theophrastus, is making a comeback. With increased funds being put into research and development by the industry, new emerging product lines are being developed for use within the automotive, clothing and home product industries.