Red wine was made from a grape variety, Cabernet Sauvignon, which was either irradiated with 1 kGy of γ-ray or treated with a commercial enzyme preparation for color extraction. Both of the γ-ray irradiation and the enzyme preparation were effective for extraction of pigments and other phenolic compounds from the grape skins, respectively. The phenolic compound indices according to the methods described by Glories indicated that the γ-ray irradiation led to polymerization of the phenolic compounds. Sensory evaluation of the treated wines revealed that the wine from the grapes irradiated with γ-ray was significantly softer than that from the enzyme-treated grapes. The improvement of sensory evaluation may be attributed to the polymerization of phenolic compounds.