They include flavor and aroma compounds such as vanillin and raspberry ketone along with wintergreen. The subtleties of the aroma and flavor compounds interact and marry with the character that evolves from the fruit, fermentation and oak producing wines of uncommonly complex character. Phenolics include natural color pigments that develop the deep color of Cabernet Sauvignon wines. Very important to these wines, too, is the flavonoid compound, Catechin. It is this compound that makes up the tannin structure of the wine.
Tannin is essential to the taste and flavor of the grapes as well as the wine.
It is the major contributor to their ability for long macerations, the process of steeping grape solids in the juice during, and sometimes beyond, the fermentation process. Basically, the longer the maceration the more extraction of phenolics occurs contributing deeper color as well as higher tannin levels that permit Cabernet Sauvignon's ability for long-term aging.