Did you know that Portugal is the world’s largest producer of cork? Half of the world’s cork is produced here, much of that within the Alentejo region, which I explored recently.
Cork is grown and harvested across the Alentejo, well suited to the hot and dry climate. Most of the processing happens in Azaruja, just to the north of Evora, an attractive historic city.
Much of the countryside of the region is covered in cork and olive trees (another key regional product).
Harvesting cork is not a business for the impatient; it takes up to 30 years for an cork oak to reach maturity for the first extraction of its outer bark – the cork – and the quality of that first year is considered to be a lower quality than subsequent harvests. The harvest takes place annually in early summer, depending on the weather. An ‘Extractor’ cuts a line around the trunk and then down to the ground before carefully wedging the outer bark away with a specialist axe – it’s a skilled job to ensure that no damage is done to the tree.
After the first harvest, the farmer waits another nine years before the next extraction, marking the dark inner bark with a large white numeral – the last digit of the current year – to tell at a glance when it was last stripped. Cork oaks are harvested for up to 150 years, though the trees can live for much longer. Interestingly, in Portugal it is illegal to cut down an oak without specific permission from Ministry of Agriculture.
Once harvested, the planks of cork are boiled to clean and soften them, which also makes them flatter and easier to work with. They can then be punched (by hand or machine) to make wine bottle corks (usually graded by quality), or otherwise cut for different uses. Leftover pieces can be ground and glued together to make agglomerated cork products. Wine bottle corks are used not only for Alentejo wine but wine all over the world.