This Take a sip of the Bonny Doon wine and notice how it feels in the mouth. Now try the Coonawarra Cabernet. Now, nibble on some bread topped with blue cheese. Try the Cabernet again. The Australian Cabernet is higher in tannins, compounds whose concentration varies from grape to grape.
Tannins are also present in wine stems and seeds and in the barrels used to age wines.
When drunk young, high-tannin wines have a drying effect in your mouth. For wines you intend to drink right away, too much tannin can be harsh. Certain foods, especially ones with a high fat content like blue cheese, can counteract the tannin in wine and make them easier to drink. The fat in the cheese coats your mouth, keeping the tannin compounds from reacting with saliva and sticking to your teeth. Some people confuse tannin and acidity in wine.