Structural, Morphological, and Kinetic Aspects of Potassium Hydrogen Tartrate Precipitation from Wines and Ethanolic Solutions

The morphology of potassium hydrogen tartrate (KHT) crystals precipitated from ethanol-water solutions and from white wines from the Penedes (Spain) is reported. In each case, the rate of precipitation is influenced by agitation, supersaturation, and temperature. Precipitation of KHT from wines differs from that from ethanol-water solutions because of impurities which affect growth and final crystal morphology. Crystal structure data, the equilibrium forms, and the growth forms of KHT are defined, and a model of impurity-crystal surface interaction has been proposed to explain crystal formation through the precipitation process and the growth process.