Take a tour of Portugal’s best-known export

Guess what kind of tree this is?

Cork oak

If you said, “A half-naked one,” then you’d be right. You’d also be right if you said it was a cork oak (Quercus suber). To be specific, it’s a cork oak that was harvested a year before the photo was taken, which is why the bark is such a rusty red. That color fades over the years as a new layer of cork grows.

These trees are a big part of the Portuguese culture, landscape and economy. I love them because they are the most environmentally benign form of agriculture I’ve ever seen. Cork oaks populate both flat landscapes and steep hillsides where nothing else can easily grow (nothing humans want to cultivate, that is, especially without terracing). They’re drought tolerant and heat tolerant, and don’t need to be hosed down with pesticides and herbicides. Mostly they’re just left alone for nine years, at which point their bark is thick enough for harvest. Then they’re marked with a painted number indicating the year of harvest, and left alone for another nine years.

Cork oak marked

Cork oaks in flat areas are often grown in company with other crops that can be harvested on an annual basis. But in the steep hilly areas, many cork oak groves are indistinguishable from native (or mostly native) forest. Since they’re not plowed or treated like orchards, they tend to thrive with native shrubs and wildflowers, creating a very rich habitat for local wildlife. Cork oak plantations are as close to wild as you can get and still call it agriculture.

And yet there is a danger that Portuguese farmers will start cutting these trees down to replace them with more profitable and vastly more environmentally destructive crops. Why? Because of plastic.

Plastic corks came out of nowhere to disrupt the cork export market, bought by big wineries because of their cheaper prices and greater resistance to the fungus that produces 2,4,6-trichloroanisole, otherwise known as TCA or “cork taint.” Cork producers were caught by surprise, having never believed that plastic could be a real competitor. They’ve made big changes since then, putting much more effort into marketing and overhauling the processing methods. The old days of letting cork slabs dry out in stacks on the ground are mostly gone, replaced with far more sterile operations designed to fight cork taint. These days, cork is extremely trustworthy, and still better than any plastic by virtue of its physical properties (almost incompressible, absorbs impact and vibration, biodegrades). And when you buy wine with a real cork, you are helping to save not just an industry and the people who depend on it, but also vast tracts of highly biodiverse landscape that enable it.

I took the above photos from a very interesting web tour through the creation of corks, published by the online wine magazine wineanorak. If you’ve ever wondered where your corks come from, and how they’re made, this will show you the highlights. The tour is in two sections: Part 1 and Part 2.

Due to its extremely light weight and resistance to both moisture and fire, cork is also used in many technical applications, including space vehicles. Did you know that 225 cork oak trees in the Alentejo (the region just north of the Algarve) were set aside to provide cork insulation for the Columbia? It was also used in all of the shuttles’ nose cones, and is now being used with the Ariane 5 rockets.

Buy cork. Sometimes, you just can’t improve on nature’s design.

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About Fletcher DeLancey

Socialist heathen and Mac-using author of the Chronicles of Alsea, who enjoys pondering science, politics, well-honed satire (though sarcastic humor can work, too) and all things geeky.
This entry was posted in culture, Portugal, science. Bookmark the permalink.

2 Responses to Take a tour of Portugal’s best-known export

  1. M. says:

    We have a history with plastic corks. They were used with cheap bad local fruit wines (we called them acid), so no way we buy a bottle with a plastic cork now 😀

  2. Ana_ñ says:

    Thank you for this post.

    “Cork Oak forests also prevent desertification and are a particular habitat in the Iberian Peninsula and the refuge of various endangered species.”

    Since I was a child and until today, I love to watch my father open the bottle of wine, smell the cork and state his opinion. And I love to do the same thing every time we enjoy a Spanish red wine Rioja Reserva or Gran Reserva.

    Long live the cork stopper!

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