If you've ever left a teabag soaking too long or eaten a thick-skinned grape and wondered about the sharp, grassy sensation interfering with the sweetness, you're familiar with tannins.

One particular characteristic of wines you'll hear talked about often is its tannins. Tannins are astringent, bitter compounds that naturally occur in plants and deter animals from eating them.

The substances, known as tannins, will naturally bind to the collagen proteins in a hide, turning it into leather as we know it. Just as they do for trees, the tannins protect hides being turned ...

Byrde, R. J., Fielding, A. H., and Williams, A. H., in Phenolics in Plants in Health and Disease, edit. by Pridham, J. B., 95 (Pergamon Press. Oxford, 1960).

Coffee, however, does. “The tannins [of red wine] don’t harmonise with the cheese,” says Alexandre Centeleghe, a Swiss wine expert. “You always pair the same aromas, and there are no ...