Cork - A Sustainable Industry

Have you noticed how so many wine bottles now have screw tops rather than corks? If you're as useless with a corkscrew as I am, you may welcome this change, but have you thought about where the cork comes from? The story behind the humble cork may persuade you that it's worth seeking out a tipple topped with a cork.

Around 50 per cent of the world's cork comes from forests in Portugal - that's 30 million corks per day! Cork comes from the bark of the cork oak, or Quercus suber, which grows in cork oak forests in the Mediterranean.

Cork oak forests                     

Cork oak forests support an incredible variety of wildlife. More than 100 species of birds can be found there, including many rare breeds. There is also the Iberian lynx - the world's most endangered big cat, which could be the first big cat to become extinct since the sabre tooth tiger - the Iberian Imperial Eagle, the Barbary Deer, and many other small mammals, bats, reptiles and amphibians. The flora is also diverse and includes over 140 species of plant with aromatic and medicinal properties, such as lavender, oregano, rosemary, mint, digitalis and rock, and many edible mushrooms, which many farm households collect to supplement their income. In many forests farmers allow their cattle to graze in the pastures round the trees, making for an even more diverse habitat.

The forests are also important for helping to contain climate change, and protecting watersheds: ‘Without cork-oak trees, much of southern Portugal and Spain would already be desert,' according to former EU forestry policy director Armando Sevinate Pinto.

Harvesting cork oak

Cork comes from the bark of the cork oak. The tree doesn't have to be cut down to harvest the cork - the cork is stripped from the tree no more than once every nine years, after which it regenerates. The trees can live for 500 years but don't produce cork suitable for harvesting until they are about 20 years old; it will be another 20-25 years before the quality of the cork is good enough to make stoppers for wine bottles. The woodlands, and the skills to harvest the cork using hand axes, are often passed down though the generations. No one has yet invented an effective mechanical way of harvesting the cork, so this is a truly sustainable industry.

So why all the screw tops?

Wine manufacturers are turning to synthetic or screw-top closures to avoid the problem of contamination by trichloroanisole (TCA) or ‘cork taint'. This can affect the taste of the wine, sometimes only to a degree that would be discernable to an experienced wine taster, but occasionally making the wine undrinkable. However, the cork is not always to blame for tainted wine - if TCA is present in the atmosphere where the wine is bottled, or on the glass, it can find its way into the wine. It is also found in bottles with closures other than cork, and also in beer, bottled water, and even raisins and coffee. In addition, TCA may be introduced to the cork by the way it is manufactured, including the chlorine-based sterilisation process. The problem became particularly prevalent in the 1980s, when many a bottle would be returned to the waiter with the complaint that it was ‘corked'.

However, cork producers have worked with scientists to address this problem and protect their livelihoods, and found that harvesting cork from higher up the trees removes the need for chlorine sterilisation, and that purification and filtration processes can further reduce the incidence of TCA. The Cork Quality Council now exists to set standards for acceptable harvesting, manufacturing and testing processes. This has now reduced the level of cork taint to much lower levels.

However, manufacturers still seem reluctant to return to natural cork and the proportion of synthetic corks and screw caps is still on the rise.

What can we do?

I did a little research at my local off-licence (I take my writing responsibilities very seriously...). They weren't aware of the sustainability issues surrounding the bottle closures, but said that now almost all New World wines came with screw caps or synthetic corks. There was, however, still plenty of reasonably priced French wine sealed with natural cork. They also assured me that if customers specifically asked for wine sealed with natural corks, they would make more of an effort to stock them.

The first step is obvious - only buy wine that is sealed with natural cork. You may have to search it out, and you may have to pay a little bit more, but if we show retailers that we want corks, the retailers and manufacturers will respond. Tell your local off-licence, wine merchant or even supermarket that you want wine with natural corks, and tell them why. You may think that your voice will be far too small to be heard by the huge supermarket chains, but they are all trying very hard to improve their green credentials (as far as customer perception is concerned, at any rate), and if we shout loud enough, they will realise that this could be another ‘green box' they can tick. Cynical, maybe, but if it helps protect the environment it's worth doing.

What to do with all these corks?

Screw caps are made of aluminium, which is easily recyclable, but they are lined with an oil-based sealant which may mean they are rejected at the recycling plant so they will still end up in landfill along with all the synthetic corks. Cork earns extra ‘green' points for being biodegradable. In theory it should be possible to recycle them into wall/floor tiles or insulating material, but recycling facilities seem to be few and far between. Branches of Oddbins, however, will collect your corks and it may be worth asking your local off-licence if they have a similar scheme - or suggesting that they start one!

However, there are all sorts of other uses for your cork collection:

• Compost them - they take a long time to break down unless you cut them into small pieces, but help to aerate the compost. If you have composted them whole you can simply pick them out of the compost when you use it and put them back in the compost bin.
• Make a noticeboard - cut them in half and glue or tack them to a piece of hardboard.
• Offer them to local playgroups or schools for arts and crafts materials.
• Put in the base of plant pots instead of old crocks.
• Slice them and glue them to the bottom of ornaments, lamps, etc. to protect the surface they stand on.
• Put them on the end of knitting needles when not in use.
• Push them over the ends of canes in the garden to avoid poking yourself unexpectedly.

I could go on... but a little searching on the Internet will provide plenty of inspiration. Please try to avoid drinking more wine just to get hold of enough corks to complete your project though!

Judy

Iberian lynx (c) Programa de Conservación Ex-situ del Lince Ibérico http://www.lynxexsitu.es

Cork oak (c) Wavering, released under Gnu Free Documentation License

Corks (c) Frank Papenbrook, released under Gnu Free Documentation License

Wine bottle (c) Cabe6403, released under Gnu Free Documentation License

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