The first process applied to the raw cork is stabilisation. We have a yard where the cork is placed in rectangular stacks some 3 metres wide, allowing air to circulate and rainwater to drain off. The cork planks are stacked on concrete beams to avoid direct contact with the ground. They are rested in this way for some 6 to 12 months in order for the cork to improve its inherent qualities before entering the preparation process.

This process is applied throughout the preparation of the planks of cork which have to be prepared to make the bundles for the production of stoppers. Bundles of approximately 300 kilos are made and boiled for some 70 minutes in clean water that has previously been decalcified and analysed periodically, in a boiler that is cleaned of earth, remains of cork or any other foreign material before every boiling operation. Once boiled, the bundles are stored in the resting area. At the customer’s request, the cork is separated into grades: 13/18, 13/18 thin, 8/13, 8/13 thin, green, thick, waste, yellow stain, wormhole and larvae.

This process is applied to all the bundles of cork used for making stoppers. Approximately 300 kilos are boiled a second time in the boiler after it has been cleaned. To compensate for the loss of water through evaporation, clean water is added without interrupting the process, which takes around 40 minutes.

In this process, first the thickness of the sheets of cork is checked. Then it is checked that the surface is free of green cork, wormholes or yellow stain. Next the sheets are stripped by machine, the width of the strips being adjusted to the length of the stoppers to be made plus 2-3 mm. The stripping operation is carried out in the horizontal plane of the plank when it was still on the tree, that is, perpendicular to the lines in the bark of the cork. The width and parallelism of the sheet are checked with a calliper, and the degree of moisture is also examined.
For the punching process, the machine is adjusted so that on punching out the sheets there are as few remains as possible of belly and bark in the stoppers obtained, but always perforating as close as possible to the belly. Finally, the stoppers are inspected for the smoothness and absence of gouge marks and grooves on the surface and for verticality and length.

We have a latest-generation electronic machine which selects and rejects very thin stoppers and loose pieces and classifies the acceptable stoppers.

A second selection is carried out by two operatives on a roller conveyor, since the human eye and the experience of our operatives are essential factors. All critical stoppers with off-aromas, dry-year lines, wormholes and larvae are discarded.

We have an advanced-technology machine which can select as many grades as the customer chooses: for example, stoppers of the grades fleur, super, 1, 2, 3, 4, 5 and 6, among others.

Once the batches have been completed, they are stored in our large warehouse in optimal conditions, duly labelled and palletised, waiting to be collected by the customer.