An experiment by Singleton and Trousdale (1992) has previously demonstrated a relationship between tannin and anthocyanin content in wine where adding a grape skin anthocyanin extract to wine helped to retain tannin. They speculated that the
incorporation of the flavylium salt and its attached sugar into the tannin polymer increased its solubility, which would help to retain tannin during fermentation. In contrast, an experiment by Oberholster, Francis, Iland, and Waters (2008) reported that adding anthocyanin to a white grape fermentation had no effect on tannin
extraction, but increased polymeric pigment formation.