Effect of Pomace Contact on Chardonnay Musts and Wines

Abstract

Wines were prepared from triplicate lots of crushed Chardonnay grapes, which were held under nitrogen for 0, 6, 12, and 24 hours of pomace contact prior to being pressed. For the musts at press and the finished wines, significant increases in pH, total nitrogen, and potassium and decreases in titratable acidity and tartaric acid were observed as pomace contact time was increased. Additionally, a significant increase in ammonia was found in the musts. In the wines, significant increases in total, flavonoid, and nonflavonoid phenols, and in malic acid were measured. The changes in concentration of these components as a function of the extent of pomace contact is illustrated by principal component analyses of the must and wine compositional data. By duo-trio tests, significant differences in wine flavor were found only between the following pairs of wines: 0 vs. 12 hours, 0 vs. 24 hours, and 12 vs. 24 hours of pomace contact. These differences, however, were too small to be characterized. No significant differences were found between pairs of these wines when compared for intensity of fruity aroma, bitterness, or acidity.