Effect of acidity correction on the solubility of tartaric compounds from wines

Abstract

The paper presents data concerning the effect of acidity correction on the solubility of potassium bitartrate and calcium neutral tartrate, as a result of acid addition (tartaric, malic, citric and succinic) in wines lacking acidity, for improving their organoleptic qualities. The solubility of these compounds was assessed by means of concentration (PC , PCT) and solubility (KST , KS ) products at −4 ºC, by the excess of KHT and CaT at −4 ºC and saturation theoretical temperatures of KHT and CaT. As a result of acidity correction, we have noticed its increase (at the same proportion for all the acids) and a diminution in pH according to added acid: tartaric, lactic, malic, citric and succinic. By adding tartaric acid, wine instability was created, because of potassium bitartrate, by increasing the values of concentration and solubility products, of KHT excess and theoretical saturation temperatures. In case of calcium tartrate, the same acid favoured wine stability, by diminishing the values of the constants. Adding the other acids in wine was good for the solubility of tartaric compounds, because, in all the cases, the values of constants characterizing solubility were diminished.