Did you know that cork has been in use for sealing bottles of wine since the 1600s? Prior to cork, the most common method of closure was rags soaked with oil. Currently, natural cork is used to seal approximately 3/5 of the world's wine bottles, while alternatives such as synthetic corks and screwcaps are used for the rest.

Cork is the bark of the Cork Oak tree, Quercus suber. Indigenous to countries of the Western Mediterranean, it thrives in the warm, dry climate. The vast majority of the world's cork is produced on the Iberian Peninsula, with Portugal alone responsible for over half of global production, and Spain responsible for about another 30%. The rest is mostly grown in other nearby countries like France, Morocco, Italy, Tunisia, and Algeria.

Cork trees are long lived, often exceeding 200 years of age. Once a tree is approximately 25 years old it may be harvested for the first time. The harvesting process is completely unmechanized, with only hand tools used to remove the layer of dead cork bark from the trees' trunks. This traditional hands-on method ensures the trees are handled carefully and are unharmed by the process. Once harvested, it will be another 9-12 years before the bark can be harvested again. Given the longevity of cork oaks, each tree will commonly be harvested approximately a dozen times over the course of its life.

After removal, the planks of bark are stacked outside and dried for several months. After drying, the cork is boiled, which disinfects it and causes it to smooth out as well as expand approximately one-fifth in size. After the cork has dried in a controlled environment, the planks are cut lengthwise into strips from which cork cylinders are punched out with a round blade. Once the cork stoppers are made, they can be printed with the logos of the wineries that will use them. Little is wasted in the manufacturing process; cork scraps, bits, granules, and irregularly-shaped pieces are processed into all manner of products from bulletin boards to ceiling and floor tiles.