Beer can absolutely have tannins, which are naturally occurring compounds (polyphenols) present in grape skins, seeds and stems, as well as grain husks and leafy herbs. Tannins in beer mostly come from the husks of barley, while the rest come from hops. Wheat beers and other styles of beer made with wheat malt are likely to be lower in tannins, because wheat grain doesn’t have a husk like barley.
However, while tannins are a benchmark characteristic of red wine, according to the “Oxford Companion to Beer,” the average amount of tannins in a finished beer is typically no more than 150 to 330 milligrams per liter. The average amount of tannins in wine, by contrast, is 544 milligrams per liter, with some reds as high in tannins as 1,895 milligrams per liter. So, it’s no wonder you aren’t used to hearing about tannins in beer.
While some brewers and drinkers don’t mind tannins in beer, others can find that the beer starts to become astringent. Astringency, or the sensation of drying the mouth out, is something that is loved in red wines, but in beer it can compete with the bitterness of the hops, which is why brewers generally try to keep tannins as low as possible.