It takes 25 years for a cork tree to be ready to harvest, but 40 years for it to produce cork that can be used in wine and spirits. A tree is harvested just once every nine years and up to 15 times over the tree’s lifetime.
The harvest takes place in the summer when the weather is settled and dry. It is carried out by hand, extremely gently so the trees are left undamaged.
After the cork has been extracted from the trees it is stacked and left to dry, then cleaned by a boiling process before being cut into strips. About 60% of a cork harvest will go to make wine corks.
The cork strips are passed by hand through machines that punch out the corks to the desired size. It’s highly skilled work as the corks are punched out at high speed.
The corks are then graded. The denser the cork the betterthe grade, so sorting is done by weight and by quality controllers who check manually.
Once the corks are ready for use, special machinery applies the CorkGuard™ membrane to each end of the cork, creating a barrier that ensures the wine comes out exactly as winemakers intend.