Discover the many secrets of Portuguese cork
From the space shuttles developed by NASA and Elon Musk’s SpaceX rocket to cork stoppers used by the world’s leading wines, Portuguese cork ("cortiça") is famous for protecting mankind’s most precious inventions…
The story of cork is as natural as it is ancient, having crossed civilizations and centuries, and always finding new ways to help man to reinvent himself and the world around him.
Millennial records show us how the insulation properties of cork were already known centuries ago. An amphora dating from the 1st century BC was found in Ephesus sealed with a cork stopper and still containing wine. In Pompeii, the ancient Roman city destroyed by the volcano Vesuvius, wine amphoras sealed with cork were also found.
Throughout history, cork was also used in objects such as shoes, buoys, and fishing gear, but also in residential construction, such as the cork applied to the walls of convent cells.
In Portugal, in the XV and XVI centuries, the capacity of cork to isolate cold and humidity was also known, having been used in the construction of the caravels which helped the Portuguese sailors to conquer the world.
In the last century, cork has been used in various other areas with new applications and utilities. Yet, in no other country has cork assumed such an important role as in Portugal, so much so that today it is a symbol of our country.
The importance of cork for Portugal
In Ancient Greece, the cork oak was a symbol of freedom and honour, the reason why only priests were allowed to cut them down. In Portugal, the cork oak is so important that no one is allowed to cut them down!
The first agrarian laws protecting the cork oak forests in Portugal appeared in 1209. Today, the “sobreiro” is classified as a National Tree of Portugal and cutting one down is prohibited by law.
Due to its Mediterranean climate and geography, cork oaks flourished naturally in Portugal, being one of its most expressive native species, especially in the Alentejo region, where the “montado” plantations play an important part in the preservation of the region’s biodiversity.
Economically, cork is also one of Portugal's biggest and most important exports. Currently, Portugal has 730 thousand hectares of cork oak forest (25% of cork oaks in the world), being the main world producer of cork with more than 100 thousand tons produced every year.
Where does cork come from, and how is it extracted?
Cork is an organic and very light vegetable material that is extracted from the bark of the cork oak (Quercus suber, or "sobreiro" in Portuguese) in a process which is 100% sustainable and does not cause any harm to the tree from which it is extracted. The cork oak is the only vegetable species able to produce cork sustainably and with the maximum quality.
The first extraction of the cork occurs when the tree reaches between 25 and 30 years, normally between June and August. From then on, the cork is extracted every nine years.
The stripping process is done manually using axes, and more than 15 can be done, interspersed for periods of nine years, throughout the life of cork oak.
It is only from the third stripping that the cork obtained has enough quality to be used in the production of cork bottle stoppers.
Transformation of cork
The transformation process begins when the raw material (bark of the cork oak) is extracted from the tree, in an ancestral process that can only be done by specialists.
After extraction, the cork enters the industrial process passing through various stages depending on its purpose and the quality of the cork. All cork not used directly in the manufacture of final products is transformed, even cork dust is used for co-generation of electricity.
Although wine and spirits bottles stoppers are perhaps the best-known cork object, today cork is used in many other areas, such as:
Fashion accessories;
Furniture and decorative items;
Components used in several industries, namely the automotive;
Musical instruments;
Sports equipment, such as competition kayaks, tennis and cricket balls, skateboards, as well as surfboards (the Hawaiian surfer Garrett McNamara, who surfed one of the biggest waves in the world in Nazaré Portugal, has a surfboard entirely made of Portuguese cork);
Space shuttles used by NASA and ESA;
Wall linings (interior and exterior), as well as flooring panels.
Benefits of using cork in residential construction
In the real estate development "Aldeia dos Sobreiros", on the Silver Coast of Portugal, modern villas were architecturally designed with beautiful cork finishings...
The recent invention of cork fabric revolutionized even further this industry and highlighted its enormous versatility and benefits: beyond its thermal and acoustic qualities, cork is also extremely resistant, 100% recyclable, and hypoallergenic... not to mention Portuguese!
Find out more...
In this podcast, Jochen Michalski, CEO of Cork Supply, one of Portugal’s biggest cork manufacturers for the wine industry, discusses the wonders of cork...