Following the harvest, the bark is seasoned and sorted prior to processing. Seasoning allows the cork to stabilize and develop a uniform level of moisture.

Traditionally, the cork planks were stacked on bare earth in the open for about six months but this practice has changed.


Under the industry's International Code of Cork Stopper Manufacturing Practice, planks are now stacked on concrete in the factory yard and stacked in a way to maximize drainage and aeration of the pile. The purpose of these measures is to reduce microbiological contamination.

From this point, all cork that is destined for wine stoppers is moved about the factory on stainless steel pallets.

The planks are then sorted to select high-quality bark suitable for wine closures. Thin bark, suitable for cork discs, is separated from the thicker bark used for natural corks.

Bark stripped from the base of the tree, known as calços, is removed. It is not used for wine stoppers as it is more prone to contamination than bark from the rest of the tree. Lower grades of cork are used in other products such as insulation sheeting and floor tiles. 

This article sponsored by Amorim Corks