Wine Must

Surplus wine grapes can be processed via ion exchange resins to reduce the salt and organic acid fractions, while purifying the glucose and fructose sugars for fermentation. Figure 1 outlines a typical layout for a wine must treatment plant. Such a system would typically apply a strong acid cation resin, followed by a weak base anion resin for deashing. This would then be followed by a bed of strong acid cation resin, in the H+ form, for pH adjustment. Color formation in the treated product can occur upon storage or at fermentation if the pH of the product is too high. Cross regeneration of the resins is required and application of HCl as the regenerate rather that NaCl is suggested. If a lighter colored wine is required the sugared stream can be decolorized using the DOWEX™ OPTIPORE™ adsorbent, which can typically remove ~50% of the color. Currently, decolorization is not done for most wine must streams, as demand for red wine is greater than that of white.