By Harold McGee
The feel of a wine is largely a matter of its astringency and viscosity. Astringency—the word comes from the Latin for “to bind together”—is the sensation we have when the tannins in wine “tan” the lubricating proteins in our saliva the way they do leather: they cross-link the proteins and form little aggregates that make the saliva feel rough rather than slick. This dry, constricting feeling, together with the smoothness and viscosity caused by the presence of alcohol and other extracted components, and in sweet wines sugar, create the impression of the wine’s body, of substance and volume. In strong young red wines, the tannins can be palpable enough that “chewy” seems a good description. In excess, they are drying and harsh.