The secret of cork: much more than a bottle stopper

Lisbon, Portugal – The sound of a cork coming out of the end of a bottle is known around the world. It often comes before occasions of celebration, a shared meal or just the quiet enjoyment of a glass of wine. But many who have participated in the simple ritual may not realize that it is also synonymous with sustainability, natural wonder, and even human ingenuity.

Cork, the humble material used for centuries to seal bottles, is a unique product not only for the way it is grown, but also for the many ingenious uses people have found for it. for him – which goes far beyond the ubiquitous bottle stops. Cork is used in everything from building spaceships to insulating houses, and it can replace rubber or plastic just about anything that needs protection from heat or vibration.

Due to the special, delicate conditions in which it grows, cork is also a powerful, natural carbon sink, meaning that it absorbs harmful CO2 from the atmosphere and locks it away.

CBS News visited the southern European country of Portugal, which produces most of the world's cork, and met with António Rios Amorim, who humbly rejects the title “King of Cork”.

“I'm just inheriting a great legacy from a family that, for the last 154 years, has been dedicating itself to cork, and really trying to develop this unique product to give it new life to him,” he said.

Amorim Cork produces more than five billion of the approximately 13 billion cork bottle stoppers produced annually worldwide. It's enough to give the family business a comfortable lead in the industry, but Amorim said finding new and innovative uses for the material, as well as sealing bottles, remained “fundamental” to the future of the empire. his

Among the lesser-known applications – and one that Amorim clearly enjoys – is the use of cork on NASA rockets. The material is mixed into the heat shields that protect spacecraft as they take off and enter the Earth's atmosphere.

Its light weight, unevenness and vibration insulating properties have made the spongy material a natural choice for some of the most important space missions, including the Apollo missions and the Mars rovers. It is also used on Elon Musk's SpaceX rockets.

“It's amazing,” said Eduardo Soares, as he gave CBS News a tour of Amorim's eclectic showroom. “Corks have this special effect, a slow burning process. It absorbs heat without transferring it.”

As head of the unit tasked with dreaming up new ways for Amorim to profit from corks unsuitable for bottle stoppers, Soares could identify every product in the room to easy.

Biodegradable cork granules replace rubber in artificial turf infill, which helps keep surface temperatures down and avoids the release of microplastics; Insulation panels that absorb vibration, making trains quieter and smoother; Children's playground flooring now has a natural alternative, usually made of synthetic materials.

For Amorim, the list of other uses for cork seems endless.

“It is very important to us that we use the raw material that we extract from nature to the last degree,” explained Soares.

Amorim is also part of a recycling initiative, aptly named The Cork Collective, which aims to help restaurants and hotels recycle cork stoppers from bottles they open, to give new life to the precious material.

Another family business in the area is Sofalca, which specializes in turning cork into natural insulation for walls and floors.

CEO Paulo Estrada gave CBS News a tour of his factory's autoclaves, affectionately nicknamed the “popcorn makers,” which cook corn kernels at high temperatures and under high pressure. The cork expands, and the natural resin glues it all together without the need for additional chemicals. A large block goes off the assembly line, ready to be cut into slabs, shaped into huge art walls or even pieces of furniture.

Estrada said the material can bring a “meditative effect” to an unimaginable part of someone's home.

“If you come close to a cork wall, you will touch, smell and feel it. No one lives without a touch,” he said.

The industry's desire to make the most of every ounce of the natural material can be explained by its biggest caveat: Cork is a layer of bark that grows only on an oak tree. Quercus Suber. It usually takes 25 years from the moment a tree is planted to be ready for the first harvest. It then takes another nine years to get the bark back.

“You have to be patient,” said Casimiro Milheiras, taking a quick break from climbing trees with a small axe. At 57, Milheiras is one of thousands of seasonal workers hired each summer to comb through Portugal's scorching Alentejo region to strip the bark by hand from the Quercus oaks.

“It's almost an art form, so you only do this job if you love it,” he said.

His 20 years of experience has taught him just how to hit the tree hard enough to go through the bark, but not so hard that it cuts into the trunk, as that would damage to the next harvest.

Natural landscape cork is not just coming to the industry, however. Environmental impact studies by international consulting firms EY and PricewaterhouseCoopers have confirmed that many of Amorim's products are carbon. negativewhich means that the entire process – from growth to extraction, transport and production – absorbs more carbon than it emits into the environment.

“There is no best example of a carbon sink in a forest like the cork oak forest, because we do not cut the tree,” explained Nuno Oliveira, “we want them to grow (for) as long as possible .”

Oliveira is the director of Amorim's forestry department, which is responsible for research and practices that keep its cork oak forests healthy. His work is helping to ensure the future of the cork industry in Portugal, and the company.

Standing in a field of planted cork oaks that were around 100 years old on average, Oliveira explained that as the trees continue to grow and regrow their valuable bark, they continue to absorb carbon – out of the air.

His biggest challenge, he said, is finding a way to shorten the time it takes for a tree's first cork harvest from the current 25 years to just 10. which CEO Amorim identified as one of the most “fundamental” questions his business needs. to answer.

“This is a gift of nature,” said Amorim. “We have to consume products with a negative carbon footprint. That means we have to plant a lot more cork trees, which will make us live in a much better world at the end of the day.”