About cork

WWF training programme on cork-harvesting methods, Tunisia
© WWF / Sebastian RICH

Precious and versatile

The precious and versatile vegetable tissue known as cork is the outer bark of the cork oak tree, not the trunk, as people might think.
Cork is most easily stripped off the tree in late spring and early summer when the cells are turgid and fragile and tear without being damaged.

The tree quickly forms new layers of cork and restores its protective barrier.

No tree is cut down. This simple fact makes cork harvesting exceptionally sustainable, leading to a unique balance between people and nature.

Natural properties
It’s a highly skilled business in the western Mediterranean, where each generation has tutored the next in a continuous process from the time of the ancient Greeks.

The harvesting cycle is 9-12 years long, and it takes at least 25 years for a new tree to become profitable.

  • The first stripping produces cork that is too hard to be easily handled. It’s used in products like flooring and insulation.
  • 9 to 12 years later a second harvest produces better material, but still not good enough for cork bottle-stoppers.
  • Only the third and subsequent harvests produce cork with an even structure good enough to be used for wine closures.
The cork oak tree will then provide a harvest for some 200 years.

It's natural, renewable, and recyclable

	© WWF / Claire DOOLE
Cork harvesting, Portugal
© WWF / Claire DOOLE
Cork-stopper processing, Portugal
© WWF-Mediterranean / Chantal MENARD
Cork’s natural properties make it eminently suitable for its principle use worldwide: as a bottle-stopper.

It is very light, yet impermeable to liquids and gases, elastic and compressible, an excellent insulator, fireproof, and resistant to abrasion.

Above all, it is completely natural, renewable, and recyclable.