Wood Science 101: Where Does Cork Come From?
By Chuck Ray | Posted: 01/12/2014 1:32PM
The fact is that natural corks are produced from the bark of the cork oak, Quercus suber. And this bark is stripped right off the live tree, in fact several times during the life of the tree. Your first reaction is probably something like, "Doesn't that hurt the tree?" Amazingly enough, the cork oaks not only survive the harvest of their bark, but seem to thrive in spite of it.
At the top is a great video shared by the International Wood Culture Association that tells the story of the trees and their unique product.
The really fascinating, and important, thing to understand about cork production is that from a ecological standpoint, we should all want more cork to be harvested and used, not less. You may be aware that there are cork substitutes, such as artificial corks and screw tops, being promoted by unscrupulous wine merchants as environmentally-friendly alternative to natural corks. Nothing could be further from the truth.
You see, use of natural corks in wine closure creates a strong market for the cork production and the maintenance of cork oak forests. As cheaper substitutes replace natural cork in the bottle, the market for the natural products shrinks and cork oak forests are converted to higher value use, such as grazing or Eucalyptus timber production. These land uses put more stress on the local ecology, as explained by The Rainforest Alliance...
"Cork oak also provides its ecosystem with several benefits. The trees help prevent soil erosion from wind and water, and increase the absorption rate of rainfall. The cork oak forests of the Mediterranean act as a barrier to the advancing process of desertification from North Africa. Furthermore, a harvested cork oak tree stores up to five times more carbon than an unharvested tree, since the tree utilizes additional carbon in the regeneration of its bark. Each year, cork oak forests account for 10 million tons of CO2 absorption." - Rainforest Alliance.org.
Digging into the topic a little I discovered this 60-year-old video online at the bottom, which I think you'll want to watch if the topic interests you. You'll see the same as in the above video, but in addition you'll see something common to practically all wood product manufacturing processes: that is, nothing ever gets wasted. Scrap from one process turns into by-product feedstock for another.
The video provided me with fond memories of scraping cork liners out of Coca-Cola bottle tops to find the images of different ballplayers - once you had them all, you could redeem your collection for a prize. I hit the gold mine when my dad brought home the whole load of bottle tops from the Coke machine in his office. Wish now I had the collection rather than the prize I redeemed it for, whatever it was.
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So the next time you pick up a bottle of wine, look for real cork. And you can contemplate your environmental activism while the glow settles in.
Just another great way to Go Wood!
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About the Author
Chuck RayDr. Charles D. “Chuck” Ray is Associate Professor of Wood Operations Research at Pennsylvania State University. His specialty is in the area of operations research, specifically those operational issues that confront the majority of the wood products sector. He previously spent 15 years in research and quality management for two large building products corporations, Temple-Inland Forest Products and Louisiana-Pacific. Ray is the sixth generation of his family to work in the sawmill industry, the Ray Brothers Lumber Company, established in East Texas before the turn of the last century. He can be reached at firstname.lastname@example.org and followed on Twitter @ChuckDRay. He maintains an Extension website for Penn State at http://extension.psu.edu/woodpro and also writes a blog on all wood issues called Go Wood which can be found at http://gowood.blogspot.com.