The Effect of Contact Time of Juice with Pomace on the Color and Tannin Content of Red Wines

Abstract

The tannin content of the juice is proportional to the contact time of juice with pomace during fermentation. However, the color density reaches a maximum well before the completion of fermentation. In 9 months' old wines the color density is roughly proportional to contact time. Astringency of the wines correlates fairly well with tannin contact. Color content of the juice cannot be reliably measured by length of fermentation, degree Brix or alcohol content of the juice. The color difference, ^ΔC, between successive samples is a reliable guide in determining the point at which the juice has attained the maximum color density. Wines from juices in this study drawn on this basis are adequately colored; and usually softer than those from juices fermented longer on the pomace.