Prefermentation cold soak (CS), is sometimes applied to improve anthocyanin extraction while limiting tannin extraction during ensuing maceration. Cabernet Sauvignon, Malbec, and Merlot grapes were processed with CS (five days at 7 ± 2°C) followed by both a short maceration (five days, CS + 5d) and a long maceration (10 days, CS + 10d) and contrasted against a control wine (10-day maceration). Wines were elaborated in triplicate (n = 3) in 100-L stainless steel fermenters. Phenolics and color components were analyzed in the finished wines and the Malbec and Merlot wines were submitted to descriptive sensory analysis. The maceration techniques had no impact on residual sugars, volatile acidity, titratable acidity, or pH. A two-way ANOVA on the phenolic composition uncovered a significant effect of cultivar on all phenolic classes. Across the three varieties, anthocyanins were more abundant in CS + 5d and CS + 10d wines, while tannins were more abundant in control and CS + 10d wines. Analysis of absorbance in the visible spectrum indicated that in Malbec and Merlot, control and CS + 5d wines achieved comparable absorbances at 420, 450, 520, 570, 620, and 630 nm, but CS + 10d had less absorbance. However, in Cabernet Sauvignon, CS + 5d wines had the least absorbance. Descriptive sensory analysis with a trained panel (n = 12) uncovered significant differences in color intensity, red fruit aroma, bitterness, and body in Malbec wines and overall, red fruit, and dried fruit aromas, sweetness, astringency, dryness, and length in Merlot wines. Overall, CS + 5d reduced bitterness, astringency, and dryness. Thus, CS followed by a short maceration time (five days) limited tannin extraction while maintaining or moderately improving selected chromatic and aromatic features relative to a control wine.

Funding Support: INTA