Tannin is most often associated with red wines and is not a taste; rather, it is a sensation in your mouth that is often described as drying or astringent. If I were to refer to a wine's backbone, I'd be talking about the tannin.
As well as from the grape itself, tannin is drawn often from the wood used for barrels in which some wines are aged or fermented.
Try this at home: Take a red table grape and peel it. Now chew the skin. Does it dry your mouth? Is it less than perfectly pleasant?
When we eat the skin while it's attached to the flesh of the grape, the tannin is balanced by the fruit, sugar, acid, etc. so we don't notice its drying qualities as much.
Cheers to you!
Copyright © 2011 Kathleen Rake. All rights reserved.