|The Know-How of Cork Harvesting.
The cork harvesting of the cork oak tree - “o sobreiro”- is the result of skillfull workers (rancho) using a special axing tool. It is a process achieved in five steps:
1. Opening-up the bark:
To open up the bark, firstly an incision is made in the thickest section of the tree trunk bark; in an almost simultaneous motion, the end of the axe is twisted so that the peeling off the bark is initiated. From this point, the skilled operator knows the extraction difficulty. If a characteristic hollow sound is heard when the tool cuts through the bark, then it means the cork is to be extracted with ease (and in large and few barks). The opposite will happen if the axe produces a short and dry sound. Generally, in the event of a cork tree where hard or difficult plank extraction is experienced, is left for a next harvest cycle. The risk of insistence can be high as the tree may be damaged, and in instances irreparably lost.
2. Peeling off:
The end of the axe is introduced in between the bark and the newly exposed surface of the tree trunk; in normal circumstances, the twisting motion of the axe, and the resulting leverage, will cause the bark to peel off.
3. Plank sizing:
It is a horizontal axe cut that shapes the size ofthe cork plank, as well as determining the amount being stripped and that remaining on the tree.
The skill of the bark strippers “os tiradores” enables the bark harvesting with dexterity and great care, without breaking it up into smaller parts. Once the first plank is removed, the operation is repeated until the intended area is completely stripped off.
Once all planks have been removed from the trunk, all the way to surfacing roots, one proceeds with the cleaning of the wedges. This consists in cutting the planks from the surfacing roots that are not appropriate to the manufacture of the natural cork stopper.
Immediately after the harvesting, each cork tree is marked with the last digit of the current year (corresponding to the year in which the harvest was made).