The Astonishing Secrets of Portuguese Cork

If, like me, enjoying a nice glass of wine is among your favourite hobbies, chances are you’ve held a bottle stopper made from Portuguese cork. Even if you prefer a fancy French champagne, the stopper is probably made of, you guessed it, cork from Portugal. Stroll down the high street of any popular Portuguese city and you’ll inevitably see various cork products and souvenirs, especially purses and hats. Portugal proudly boasts as a leader in cork production. Almost 35% of cork forest worldwide is in Portugal and their annual production is 150,000 tons, virtually half of all production in the world. From NASA heatshields to badminton shuttlecocks to the world’s first postage stamp made from cork (yes, Portuguese!), let’s look at the role of Portuguese cork.  

What is cork and what’s so special about it?

Cork is a natural material, specifically the bark of a type of oak tree (Quercus Suber L.) with evergreen leaves. This amazing tree has an average lifespan of around 270 to 300 years and is known for its prodigious capacity for regeneration. I can attest to that – after all around us was burnt to a crisp in the October 2017 fires, the cork oaks have largely bounced back, sprouting new leaves the following spring. Although it may sound like a fairly simple material, cork has some very special characteristics: it’s extremely light, elastic and compressible, highly resistant to abrasion, fire retardant, impermeable to liquids and gases and, last but not least, has excellent thermal and acoustic insulation qualities.

Cork, the wonder product that spans millennia

The first instances of cork usage go way back in time. In 3000 BC, for example, Egypt, Babylon and Persia were already using cork in fishing tackle. Every now and then, throughout history, new uses for cork have been invented including several kinds of military equipment in World War II.  The importance of cork in Portugal was officially recognised with the introduction of the first known agrarian laws protecting cork oak forests in 1209. Cork trees are still a protected species so you need special authorisation if you ever need to cut one down and there are rules that govern how thick the trunk must be before you can start stripping bark. Look closely at the exquisitely carved stone in the UNESCO World Heritage Convent of Christ in Tomar, including the famous Manueline style window from the early 16^th century, and you’ll notice cork oak trunks and cork buoys, which demonstrates the importance of this material in the Portuguese Discoveries. In 1560, the friars of the incredibly poor and small Convento dos Capuchos, one of my favourite Sintra sights, used cork in several parts of the convent to cover roofs, windows, seats and even doors, mostly to protect themselves from the cold humid weather of the region. The Carmelite monks in Bussaco in Central Portugal used cork in a similar way, which you can still see when you visit. However, it wasn’t until around 1700 that cork stoppers started being used in Portugal and this usage grew with the expansion of the port wine trade some 70 years later.  In later years, the decorative potential of cork was explored in the Chalet da Condessa d’Edla in Sintra.

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Cork harvesting

One of the many great things about cork is its sustainability. The bark is harvested every 9 years throughout a tree’s lifetime, with no need to cut down or damage the trees. The number you may see painted on a tree trunk indicates the year it was harvested. Cork forests are a long term investment, or as the saying goes in Portugal, you plant them for your grandchildren. A cork oak tree will only be ready for its first harvest 25 years after being planted. The first and second harvests, however, will produce cork that’s not good enough to be used as bottle stoppers – that material will instead be ground up and used to make several different products, from fashion items, to building materials or fishing products, so there is no waste.  These long time frames mean that the bottle stopper you’re holding in your hand comes from a tree that is at least 43 years old and may be older than you! Águas de Moura in the Alentejo region actually boasts the oldest and most productive cork oak in the world. The wonderfully named Whistler Tree, due to the sound of the songbirds that perch in its branches, was planted in 1783 and was given the distinction of being named European Tree of the Year in 2018. Cork harvesting is a complex and fascinating process, almost like a ritual, that should only be carried out by specialists as it takes a lot of experience and manual skill to harvest the cork without harming the tree. The harvest usually happens between May and September and no machines whatsoever are involved in the process. The tiradores (cork strippers) work in pairs with handheld axes, one of them on the ground and the other in the tree. They first make cuts at both the top and bottom of the tree trunk and then peel the cork off.

Cork forest tours in Portugal

Portugal is home to about 34% of the total of cork forests in the world and produces more than 50% of the world’s cork supply. You’ll find cork forests in most parts of the country but especially in the Algarve and the Alentejo plains. In these parts of Portugal, you’ll be able to find the montado: the word refers to a mixed landscape and ecosystem that revolves around cork oak forests with shrubs, pastures and farmed areas. In the era of massive-scale agriculture, this biodiversity was stripped right back but there is a growing movement towards reviving this more sustainable system, which also helps to conserve water, protect the soil and support wildlife. For a first-hand experience of life on a family-owned cork plantation near the medieval village of Redondo, consider visiting an authentic cork farm in the Alentejo region. The guided tour includes an authentic Alentejo lunch. The same cork estate offers a 2-hour vintage Land Rover tour of the farm. You can also take this Megaliths and Cork Forest Guided Tour from Evora. You can also stay overnight at their farm, Herdade da Maroteira a great experience if you want to relax and enjoy the estate’s wine or to give your kids a chance to get to know the animals.

Cork factories

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Depending on where you go in Portugal, and the time of year, you may see lorries laden with curved gnarly cork barks on their way to a processing factory. I went on a factory tour at Nova Cortiça in São Brás de Alportel in the Algarve and when I arrived, there were stacks and stacks of bark drying in the sun. After 6 months, these barks are boiled to remove impurities and and flattened to make them easier to work with. I watched, transfixed, as workers with sharp knives swiftly and expertly sorted stacks of flattened bark according to depth and quality whilst deftly trimming them into more uniform shapes that can be passed through the various machines. Inside the factory, I learned more about bottle stoppers than I ever realised there was to know. Nova Cortiça specialise in producing the cork disks than can be used to create a safe barrier between a stopper made from ground and glued pieces of cork and the precious wine. Even champagne corks use these disks – take a closer look next time you open a bottle. They also produce single-cut corks of varying quality, that are used with better quality wines.  Any off-cuts that can’t be used for bottle stoppers get ground up and used to produce other cork products such as cork leather, a vegan, eco-friendly fabric that is durable and waterproof and therefore ideal for making handbags, hats and other accessories. You can buy such items online through the Portuguese company Cultura Portuguesa. If you would like to learn more this cork factory and shop tour will give you an excellent understanding of the local cork industry. 

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Cork crafts, souvenirs and other uses

Being flexible and lightweight, cork can also be used in a series of everyday accessories like mouse mats, cork yoga mats, woodwind instruments, inside baseballs, tennis and cricket balls, golf accessories, to make furniture, kitchenware, toys, rugs, cork umbrellas, dresses or in one of Garrett McNamara’s surfboards. Cork’s unique sound and heat insulation qualities make it a wonderful material for floor tiles (they are so much warmer and forgiving than ceramic ones), sound-proofing materials and in several of NASA’s projects since the 1960’s, including the Apollo and Columbia space shuttles as well as the Mars Rovers. In these cases cork is fundamental in protecting against the heat caused by friction when high speeds are reached.

Cork industry in Portugal

Portugal currently has about 670 companies working in the cork industry which, among other items, produce an average of 40 million cork stoppers per day. These companies employ about 8,300 workers with thousands more jobs in forestry exploration and other related employment, like tourism, restaurants and livestock farming. Of course, modern technology has affected the impact of cork on local economies. For a glimpse into the heydays of a more manual cork industry, head to the Algarvian town of São Brás de Alportel. The Costume Museum has a whole area devoted to the history of cork production and the lives of the families involved, from owners to workers.  Discover other cool places to visit in the Algarve in this article.

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