In 1974, Pascal Ribéreau-Gayon published a color plate that revealed a mysterious reality: by themselves, anthocyanins are not very soluble in 12% alcohol and confer only a light pink color.3 If wine is a solution, red wine is not possible. He then showed how, in combination with tannins, the anthocyanins become deep red. Although no one knew what to make of this at the time, he was really demonstrating that color and tannin together form colloidal structures.
