Where Does Cork Come From?

Recently, there was an article with a very detailed description of where cork comes from. Cork in the wine business is synonymous with closures for wine bottles which have been around since glass bottles gained popularity in the 18th century. Although currently, there is a move away from cork to screwcap closures.
Cork comes from the oak tree, a slow-growing tree which takes decades to produce good quality cork, the bark of the tree. It is unique in its ability to regenerate its bark. Cork is durable, waterproof, light and pliable making it ideal for use in all kinds of products.
Portugal is the world's largest cork producer and the cork oak is its national tree. The cork trees are protected by law in Portugal, so it’s forbidden to cut them. Most of the cork produced in Portugal grows in the gently undulating hills and plains in the south of the country, in an ancient agroforestry system known as montado. A montado is a savannah-like ecosystem combining cork, holm oaks and olive trees with pastures, grazing livestock, crops and fallows. In addition to jobs, the forests where cork grows provide food and shelter for animals, all while sequestering carbon dioxide. Coruche, a rural area south of the Tagus River is known as Portugal’s “cork capital".
The process of harvesting cork takes precision and years of practice. During late May and August when the tree is in its active phase of growth, the bark is easier to strip without damaging the tree turnk. The stroke of the ax must be strong, but also delicate to avoid hitting the inner bark and damaging the tree to carefully peel away the bark from the tree trunks. Once the bark is removed, workers write the last number of that year with white paint on the exposed golden brown trunk. The bark will slowly grow back and be ready for another harvest after nine years.

The harvested planks of cork will then be stacked outdoors in storage areas exposed to air and sunlight. After six months of aging to remove moisture, they will be sorted according to their thickness and quality, then boiled to clean impurities and make the material softer and easier to handle.

Aged oak being boiled:

The cork planks are trimmed and punched to form natural cork stoppers and the leftovers are ground into granules and pressed together to form cork sheets or blocks.
Cork is experiencing a revival as more industries look for sustainable alternatives to plastic and other materials derived from fossil fuels. While most cork is still used for bottle stoppers, over the last decade different industries have been finding new uses for it. The bark is now used for flooring and furniture, to make shoes and clothes and as insulation in homes and electric cars. Portugal’s exports reached an all-time high of 670 million euro ($728 million) in the first half of 2023.
Recycled cork can also be crushed and composited to make other products. In Portugal, Green Cork, a recycling program started by the environmental organization Quercus, has collected and recycled more than 100 million cork stoppers since 2009. A similar initiative, ReCORK, exists in the United States. We use engineered cork as a bottle closure for our wine and I was glad to read that it is green and sustainable.
References:
1. Marta Vidal, This ancient material is displacing plastics and creating a billion-dollar industry, The Washington Post, February 3, 2024.