is a secondary tissue, made up by the whole of dead cells that the oaks
naturally produce from the trunk. These cells, joining one another without
space within them, create a light but thick compound, at the same time
weatherproof and incorruptible, which make the bark gas- and liquid-proof.
This is the reason why it’s turned to be the ideal material for
several industrial applications. Besides the famous bottle-corks, cork
is used to produce excellent thermal-acoustic insulator, floats, gaskets,
precious coverings and tapestry and fine alternatives to tiles, marble
The cork oak grows spontaneously in the mild Sardinian climate and still
holds out against the unceasing danger of fire and deforestation. The
extraction takes place in summer, when hot and dry climate makes easier
the detachment from bark and not before the tree is 25/30 years old
and its trunk has reached a girth of at least 60/65 cm. The height of
the cut is always in proportion to the size of the plants. The first
cork extracted (the male one) is called “sugherone” or male
cork; it’s greyish and rough, of low quality and is sent to grinding,
to be agglomerated and form panels. This is the first bark product by
the tree, that this latter will keep for all its lifetime in the parts
of the trunk and in the branches, which doesn’t undergo extraction.
From the second extraction and the followings, a different kind of bark
will be taken out, it will be first-rate cork and called female, or
Between two consecutive barkings, there must be a break of at least
ten years, during which extraction is strictly forbidden. Cork
can be worked after a period’s ripening that goes from a few months
to many years. The next stage is to boil cork for about one hour, in
a boiler at a very high temperature, to make it flexible and therefore
workable. After a further ripening, cork production starts, often targeted
to the main aim: the bottle cork. Actually, even if it has to face more
and more often the competition of synthetic material, he stands always
foremost. Cork market price is determined by several factors: bark age
(the farther off the previous extraction, the thicker - and costly -
the bark will be); possible impurities which would depreciate its quality;
area and climatic exposure of trees.
Quality goes from “First” to “Fourth” level,
according to material’s compactness. The reject, represented by
inferior quality cork is called “macina” (grindstone) and
it’s obviously to be sent to grinding.
Besides the above-mentioned uses of the product in industry and building
trade, we can’t forget the production of typical Sardinian souvenir.
Moreover a new tissue has been recently patented, completely cork-made,
for dresses’ making up.
Once cork manufacturing was organised in stages: extraction, boiling
and ripening and the final result is the “quadretto”, from
which the bottle cork would later be trimmed, exclusively by hand. This
kind of production is nowadays disappearing, owing to the use, more
and more widespread, of machines, that make work ten times speedier
than before. Suffice it to think that a craftsman of the old school
could produce 2000 to 3000 “quadretti” a day, whereas, with
machinery help, production exceeds 20.000 pieces a day.
The old craftsman is disappearing, leaving its place to the new technologies
that need, anyway, sizeable investments, creating always-new employment
opportunities, and certainly this isn’t a marginal factor. The
old worker who, sitting at his bench, ground out a great deal of “quadretti”
with mathematical precision, and sorted them out according to their
size and quality, has nowadays given way to the hollow punch, which
is of course handled by skilled hands, and which trims an enormous amount
of bottle cork almost ready to be sold.
Going around the many factories in Gallura, you could still be so lucky
as to chance upon a “quadrettaio”, the old craftsman, but,
unfortunately, the merciless market logic made him more and more a rare
sight threatened with extinction. Finally, we would like to remark that
most of required machinery to go through the different stages is produced
in loco by far-sighted craftsmen, who employed their time and resources,
betting again on this wonderful material called cork.