The secrets 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 all over the world. It often precedes moments of celebration, a shared meal or simply the quiet tasting of a glass of wine. But many who have participated in this simple ritual may not realize that it also stands for sustainability, natural wonder, and even human ingenuity.

Cork, the humble material used for centuries to seal bottles, is a unique product not only in the way it is grown, but also in the plethora of inventive uses people have found for it, which go well beyond beyond the omnipresent bottle caps. Cork is used in many areas, from building spacecraft to insulating homes, and it can replace rubber or plastic on just about anything that needs protection from heat or vibes.

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

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

“I’m just inheriting a huge legacy from a family that for 154 years has been dedicated to cork and really trying to develop this unique product to give it a new life,” he said.

Amorim Cork produces more than five billion of the approximately 13 billion cork bottle stoppers produced worldwide each year. That’s enough to give the family business comfortable supremacy in the industry, but Amorim said finding new and innovative uses for the material, beyond bottle sealing, remains “fundamental” for the future. of his empire.

Among the lesser-known applications – and ones that Amorim clearly appreciates – is the use of cork on NASA rockets. The material is mixed into the heat shields that protect spacecraft as they leave and re-enter Earth’s atmosphere.

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

“It’s remarkable,” said Eduardo Soares, as he gave CBS News a tour of Amorim’s eclectic showroom. “Cork has this very particular effect, a slow combustion process. It absorbs heat without transferring it.”

As head of the unit tasked with devising new ways for Amorim to profit from cork that isn’t suitable for bottle caps, Soares was able to easily identify every product in the room.

Biodegradable cork granules replace rubber in artificial turf infill, which also helps keep surface temperatures low and prevent the release of microplastics; Insulating panels that absorb vibrations, making the wagons quieter and smoother; Children’s play area flooring, typically made from synthetic materials, now has a natural alternative.

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

“It is very important for us to use the raw materials that we extract from nature to the last limit,” 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 the bottles they open, in order to give new life to this precious material.

Sofalca is another family business active in the field, specializing in transforming cork into natural insulation for walls and floors.

CEO Paulo Estrada gave CBS News a tour of his factory’s autoclaves, affectionately known as “popcorn machines,” which cook cork pellets at high temperatures and intense pressure. The cork expands and its natural resin bonds everything together without the need for added chemicals. A large block comes off the assembly line, ready to be cut into plates, shaped into huge art walls or even furniture.

Estrada said the material can give an otherwise modest part of someone’s home a “contemplative effect.”

“If you approach a cork wall, you will touch it, feel it and smell it. No one remains indifferent,” he added.

Companies’ desire to make the most of every ounce of the natural material can be explained by its greatest reserve: cork is a layer of bark that grows only on the Quercus Suber oak tree. It typically takes 25 years from the time a tree is planted for it to be ready for its first harvest. It then takes another nine years for the bark to grow back.

“You have to be patient,” said Casimiro Milheiras, taking a short break after climbing trees with a small axe. At 57, Milheiras is one of thousands of seasonal workers hired each summer to travel through Portugal’s torrid Alentejo region to manually peel the bark of Quercus oaks.

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

His 20 years of experience have taught him exactly how to hit the tree hard enough to pierce the bark, but not so hard as to sever the trunk, as that would compromise the next harvest.

But the natural landscape from which cork comes is not only important for the industry. Environmental impact studies carried out by international consulting firms EY and PricewaterhouseCoopers have demonstrated that many of Amorim’s products are in fact carbon-intensive. negativemeaning that the overall process – from growth to extraction, transportation and production – absorbs more carbon than it emits into the environment.

“There is no better example of a carbon sink in a forest like the cork oak forest, because we don’t cut down the trees,” explained Nuno Oliveira, “we want them to grow [for] as long as possible.”

Oliveira is the director of Amorim’s forestry division, responsible for the research and practices that keep its cork oak forests healthy. His work helps secure the future of the Portuguese cork industry and the company.

Standing in a field of planted cork oaks that averaged about 100 years old, Oliveira explained that as long as the trees continue to grow and regrow their precious bark, they will continue to suck carbon from the air.

His biggest challenge, he said, was finding a way to reduce the time it takes to first harvest cork from a currently 25-year-old tree to just 10 years, which CEO Amorim highlighted as one of the most “fundamental” questions his business needs. to answer.

“It’s a gift of nature,” Amorim said. “We need to consume products with a negative carbon footprint. This means we are going to have to plant a lot more cork oaks, which will ultimately make us live in a much better world.”