Cork is produced by a species of oak tree called Quercus suber, it grows well in the western Mediterranean where it favours the mild winters and plenty of sunshine. It grows wild in the Algarve and is not usually grown in plantations so you are likely to come across it in the mountains along with other useful trees such as olive, almond and carob. Portugal produces half the worlds cork, most of which is used to make stoppers for wine bottles. The best quality cork for stoppers is said to come from the Algarve and parts of the Alentejo.
Cork production has remained largely unchanged for centuries. The cork oak is not a fast growing tree so it must be at least 25 years old before the first harvest. This will be inferior cork and unsuitable for wine stoppers. Cork can then be stripped from the tree every nine years but it will be the third harvest before cork for stoppers is good enough. Following harvest the tree is painted with the year it was undertaken, 5 painted on the tree trunk signifies it was harvested in 2015 it therefore can’t be harvested again until 2024. Producing cork is a long, slow process.
Cork is initially only taken from the lower part of the trunk. As the tree gets older it can be taken from greater heights as the tree grows. Cutters work in teams of two, one climbs the tree and the other remains on the ground. They carefully strip away the cork layer using axes but extreme care is needed not to damage the living layer below as this is where the new cork will be regenerated from. Cork is usually removed in the summer months between May and July, this gives it the remainder of the summer to dry out.
Cork oaks can live for over 200 years and are protected by law. The law regulates the frequency of cutting at nine years and it is illegal to cut down a cork oak even if it is dead or diseased.
Once the summer is over the cork is sold to cork factories. The town of Sã0 Brás De Alportel is the epicentre of the cork processing industry in the Algarve. The industry has declined in the area and much of the finishing of cork products is now undertaken in northern Portugal. When the cork first arrives at the factory it is stored outside in stacks two pallets high. The curvature of the bark can clearly still be seen at this stage.
The cork is then taken into the factory and placed into a boiling water tank. This kills any insects and microbes that may be on or in the cork but also softens it so that it can be flattened. The boards are then stacked and left to dry.
The boards are then examined by eye for the quality of the cork. The person that does this is highly skilled and is looking for imperfections and patches of retained moisture. Strips are cut away until the best, most even cork is left. The offcuts are bagged and used to make cork tiles and insulation material. Nothing is wasted here.
Below shows two pieces of cork, the one on top is much higher quality for making bottle stoppers.
Today the cork is now sent to other factories to be turned into the final products which can be anything from the aforementioned bottle stoppers to floor tiles, thermal and acoustic insulation boards, clothing, shoes, handbags, purses and shopping bags. The amount of cork that is processed for use is staggering just from this one factory
Corks for bottles used to be punched out individually from strips of cork cut to the required depth
Today the demand for bottle stoppers is huge. Something like 80% of the 20 million bottles of wine produced each year are stoppered using cork. It is not surprising therefore that the process is now fully automated and can produce thousands of stoppers per minute.
A fascinating visit to one of the traditional industries of the Algarve.