TY - JOUR T1 - Comparison of Pre- and Post-Fermentation Ultrafiltration on the Characteristics of Sulfited and Non-Sulfited White Wines JF - American Journal of Enology and Viticulture JO - Am J Enol Vitic. SP - 182 LP - 185 DO - 10.5344/ajev.1990.41.2.182 VL - 41 IS - 2 AU - C. A. Sims AU - R. P. Bates AU - R. P. Johnson Y1 - 1990/01/01 UR - http://www.ajevonline.org/content/41/2/182.abstract N2 - The effects of pre- and post-fermentation ultrafiltration (UF) (30 000 MWCO membrane), and the combination, on the color and sensory characteristics of a white Euvitis hybrid and a Vitis rotundifolia cultivar produced with and without added sulfites were compared. A pre-fermentation UF only slightly reduced the brown color in the non-sulfited Euvitis juice, but reduced the polyphenoloxidase activity and reduced browning and increased the varietal aroma intensity in both sulfited and non-sulfited wines. UF after fermentation was not nearly as effective in improving the color of the Euvitis wines and did not increase the aroma intensity. UF had only a minor impact on the initial color of the V. rotundifolia wine, but all UF treatments improved the color stability of the non-sulfited wine. UF after fermentation, but not before, reduced the aroma intensity of the V. rotundifolia wine. ER -