Profiling Zinfandel Wines by Sensory and Chemical Analyses

Twenty-four Zinfandel wines were evaluated by standard chemical determinations and by sensory descriptive analysis using trained judges. The Zinfandels came from several different regions in California from the 1980 and 1981 vintages and ranged from 12.7% to 15.7% ethanol (v/v). Variations in the chemical composition and in the aroma and flavor by mouth intensity ratings were examined by Principal Component Analyses (PCA). Wines of low, medium, or high ethanol levels were differentiated in PCAs of flavor by mouth terms and of the chemical data. Low-alcohol wines were lowest in perceived viscosity and intensity of bitterness and berry and black pepper flavors perceived orally, while being chemically characterized as having lower phenols and physical viscosity. In addition, the higher-alcohol wines had higher titratable acidity and slightly lower pH, reflecting the effect of winemaking practices rather than the grape composition. In these 24 wines, no characteristic aromas were shown to occur as a function of ripeness of the grapes as expressed by wine ethanol concentration. Wines from the 1980 vintage differed from the 1981 wines in aroma and flavor by mouth. The 1980 wines were higher in black pepper, phenolic, and ethanol aromas, black pepper by mouth, and perceived viscosity. By none of these PCAs was there any distinctive regional characterization.