What is a cork made out of?

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Dear Dr. Vinny,

What is a cork made out of? Is it wood?

—Jon B., Beaumont, Texas

Dear Jon,

Kind of. Cork is made from the bark of a tree, Quercus suber, or the cork oak. These trees can grow pretty big, and they have really thick, rugged bark. One plus side to cork cultivation is that you don’t have to chop down a tree to make corks—you can harvest the bark without harming the tree, and then do it again in about another 10 years.

Cork is a pretty remarkable material—it’s elastic, strong and relatively impermeable to air. But there are some downsides to cork, too, including its susceptibility to the chemical compound TCA, or 2,4,6-trichloroanisole, and its musty, “corky” notes.

—Dr. Vinny

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