A Review of the Effect of Winemaking Techniques on Phenolic Extraction in Red Wines

Am. J. Enol. Vitic. 56:3 (2005) 197 Phenolic compounds are important to red wine quality because they impact color, mouthfeel, and ageability. Although phenolics are present in grape juice, the amount is greatly increased in wine because of their greater solubility in ethanol than in purely aqueous solutions. Typical levels of the major grape phenolics present in red wine are shown in Table 1. Anthocyanins, flavanols and their polymers, and polymeric pigments resulting from the reaction anthocyanins with polymeric flavanols are the phenolic compounds with the greatest sensory impact in red wine. While anthocyanins and polymeric pigments give red wines their color, flavanols and their polymers are responsible for bitterness and astringency (Joslyn and Goldstein 1964, Arnold et al. 1980, Clifford 1986, Guinard et al. 1986, Robichaud and Noble 1990, Breslin et al. 1993, Naish et al. 1993, Fischer et al. 1994, Thomas and Lawless 1995, Thorngate and Noble 1995, Kallithraka et al. 1997, Sarni-Manchado et al. 1999). The polymeric flavanols are also referred to as tannins. Color is probably the most easily recognized aspect of red wine quality. Anthocyanins and polymeric pigments both contribute to wine color. Anthocyanins are the pigments that give black and red grapes their color. Once the grapes are crushed, polymeric pigments begin to form and their amounts continue to increase with time (Somers 1971, Nagel and Wulf 1979). By the end of the first year, 50 to A Review of the Effect of Winemaking Techniques on Phenolic Extraction in Red Wines