Tannins?

[mrdutton]

Courtesy of www.stratsplace.com:

One of the major components of red wines .. this astringent stuff is found in the seeds, skins and stems of grapes. During the making of wine, the longer the wine stays in contact with these .. the more tannin there is. It helps to age red wine but like everything else, it must be in balance with the fruit. Many young reds suffer from being too tannic. Many times fining* is used to remove some of the tannins. The best way to describe how it effects your palate is to brew some VERY strong tea. That "mouth puckering" that you get along the sides of your mouth and tongue is caused by tannin.

Hope above helps a bit........

Also:

When you see a fresh water stream and the water is colored brown, it is brown because of the tannins is has absorbed from leaves and other plant materials that have fallen into the stream. If you taste it, it is somewhat bitter and puckery, just as in the strong brewed tea example noted above.