Effect of macerating enzymes and postfermentation grape-seed tannin on the color of cynthiana wines

Macerating enzymes and postfermentation enological tannin were used on Cynthiana (Vitis aestivalis) to examine effects on color extraction and retention. Color measurements of must treated with five enzyme preparations (Trenolin Color DF, Lallzyme EX-V, Crystalzyme Tinto, Rohapect VR-C, and Vinozyme G) and a control with no added enzyme were compared during fermentation on the skins. For all treatments, maximum red color occurred by day 3 of fermentation and then declined. At the end of alcoholic fermentation, Trenolin Color DF, Lallzyme EX-V, and Vinozyme G had higher percentages of red color and lower percentages of blue and yellow color than the control. A postfermentation grape-seed tannin treatment (with or without Grap'TanPC) was established after combining replicates of each enzyme preparation. In newly bottled wine and wines stored for I I or 22 months, there were small but significant differences because of macerating enzymes and tannin addition. Lallzyme EX-V and Vinozyme G promoted more polymeric pigment formation and had more ionized anthocyanin than the control. The addition of Grap'TanPC mimicked the effect of the enzyme preparations and increased anthocyanins, polymerization, ionized anthocyanin, and yellow color. Time in the bottle had a greater impact on color than enzyme or tannin. Although statistical differences existed for color in both enzyme preparation- and tannin-treated wines, the magnitude of the color differences was small and may not be commercially important.