14 November 2010

Choose cork!


The Alcornocales Natural Park forms part of a belt of of cork-oak forests stretching across southern Europe and northwest Africa, and cork has played a large part in the economy of Alcalá de los Gazules for over a hundred years.

Cork is a natural product found between the outer bark and the woody inner stem of the cork-oak, Quercus suber or alcornoque ("Alcornocales" means cork-oak groves).  Once the tree is 25 years old the cork is harvested by hand, taking care not to damage the capa madre (mother-layer) or cork cambium from which the cork layer will eventually grow back.  Following the Civil War when traditional cork-cutters were for various reasons thin on the ground, Franco sent in unskilled workers who did irreversible damage to thousands of trees because they weren't aware of the significance of this.

The colour of a freshly-peeled tree is rich chestnut red, like a conker, but it quickly turns almost black.  Cork is is a beautiful example of an environmentally sustainable industry, because the tree is not destroyed and after nine or so years it can be cut again for a new harvest.

The cork-cutting teams go out into the Alcornocales between June and August.  The slabs of cork are taken to various processing plants, where they are boiled to improve elasticity and remove impurities, then scraped, trimmed and pressed into "tablas" or boards.   These are weighed and graded according to their thickness and quality.  The good stuff will go to the wine industry to be made into bottle stoppers, especially the sherry producers around Jerez, while the rest will be sent to distant factories to be made into floor tiles, insulating materials, notice-boards, tiles, fishing floats, gaskets, coasters, tennis rackets, footwear or whatever. It is a source of despair for locals that there are no such manufacturers in the immediate area.

Local writer Juan Leiva describes how in the 1940s the cork teams used to camp out in the hills and only return to town every couple of weeks for a change of clothes.  Arrieros leading long strings of mules, each bearing an improbably large load of cork, would come into the town where they would be met by dealers' reps and the cork loaded onto lorries, equally precariously balanced.

Mules and donkeys are still used today to get to the more inaccessible areas of the park.

Before the mid 17th century, oil-soaked rags were used to seal wine bottles; it was a monk called Dom Perignon who first experimented with cork.  It is an ideal material for this purpose, being elastic and virtually impermeable; once inserted into the bottle it expands to form a tight seal.

The increasing use of synthetic stoppers and screwtops seen over the past 20 years has caused problems for the cork industry, but for fine wines only cork will do, because it allows oxygen to interact with the wine during the ageing process.  One of the reasons for replacing cork wine bottles was to eliminate the problem of cork-taint, caused by a chemical called trichloroanisole (TCA).  However modern producers have developed a method to remove TCA from cork, and aided by pressure groups concerned with the environmental impact of non-recyclable materials, there is no good reason why the trend should not be reversed.

YOU CAN HELP!  Choose cork - the World Wildlife Fund's campaign to protect cork oak forests.
Cork Screwed? Environmental and economic impacts of the cork stoppers market (PDF)

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