Catechin or epicatechin condense with malvidin 3-glucoside in the presence of acetaldehyde first giving two highly colored compounds in a stable ratio during their formation. That ratio depends upon the used phenol. Malvidin 3, 5-diglucoside reacts also, but very slowly. In a second time two other compounds are formed and precipitation occurs. Several pigments are present in the precipitate. A reaction scheme is proposed to explain the formation of the condensation products.