TY - JOUR T1 - A New Indicator for Total Acid Determination in Wines JF - American Journal of Enology and Viticulture JO - Am J Enol Vitic. SP - 174 LP - 177 DO - 10.5344/ajev.1966.17.3.174 VL - 17 IS - 3 AU - Gilbert Wong AU - Arthur Caputi, Jr. Y1 - 1966/01/01 UR - http://www.ajevonline.org/content/17/3/174.abstract N2 - The true endpoint of the total acid titration curve in wine seems to be quite close to pH 7.7. Utilization of this pH permits accurate determination of the endpoint electrometrically since the curve is steepest in this region and a small amount of titrant will shift the pH radically. In cases where a pH meter is unavailable, an excellent indicator, Cresol Red, which has a very distinctive color change at this pH, is available. Superior standard deviation figures are found for this analysis when Cresol Red is substituted for phenolphthalein. The answers obtained by titrating to pH 7.7 or the Cresol Red endpoint may be converted to those found with phenolphthalein or pH 8.4 by multiplying by a factor of 1.05. ER -