Corking Sustainablity: A Green Shift from Plastic

An article in the Washington Post by Marta Vidal reports that a city in Portugal called Coruche is known as the “cork capital”. The practice of extracting the cork in the summer months is thousands of years old. It was practicted in the western Mediterranean by Egyptians, Persians, Greeks and Romans. It was used to make fishing gear, sandles, and many types of containers from jugs to barrels.

Now it is hoped that cork may become a more sustainable alternative to plastic as other materials are being made from it. From shoes to cloths, to insulation in houses and in electric cars. Portugals exports reached a high of 670 million euros ($728 million) in the first half of 2023.

Not only does this new industry create more green jobs, but the forest where it grows provides food and shelter for animals, while sequestering carbon dioxide. Cork trees do not need to be cut down so they continue to sequester carbon throughout the lift of the tree which can last for 200 years or move.

Harvesting cork is a high paying job because it requires skill to remove the cork without damaging the living tree. It can only be harvested between May and August when the tree is in its active growth phase. Once the cork is removed, it will grow back slowly and be ready to harvest again in nine years.

The cork is then laid out to dry for six months, then boiled to remove all impurities, making the cork softer and easier to handle.

Cork is still primarily used to stop bottles, but is also increasingly used for other items such as insulation. It is completely biodegradable and durable and can remain unchanged for as long as 50 years.

Cork also stores carbon which is good for the environment. Recycled cork is even being crushed and recycled to make other products. The Portuagese company, started by an environmental organization, Green Cork, now collects and recycles cork. It has recycled more than 100 million cork stoppers since 2009.

In the United States an initiative called ReCORK is also recycling cork.

Cork is endemic to the Mediterranean area with the most extensive forests being found on the Iberian Peninsula. These cork oaks are so loved that they are named the national tree of Portugal and are protected by law.

A materials expert at the University of Averio in Portugal, Rui Novais, says, “We are seeing a growing interest in cork as a sustainable material. Compared with materials like polyurethane form [used for thermal insulation], products made with cork require less energy and produce less CO2 emissions… It’s an extraordinary, renewable and biodegradable material. It’s also very durable. It has been demonstrated that cork products remain virtually unchanged for more than 50 years.”

Cork Oaks are part of the natural ecosystem of the Iberian peninsula and other areas in the Mediterranean. In Coruche, people still repeat an old saying, “Those who care about their grandchildren plant cork oak trees.”