The General Relationship Between Potassium, Sodium and pH in Grape Juice and Wine

The general relationship between the concentrations of the cations, potassium and sodium, and acidity measures of grape juices and wines are presented. The pH is expressed as a function of the titratable acidity, the potassium and sodium contents and the tartrate to malate ratio. The graphical representation of the relationship provides a means of following the changes in the organic acid content, titratable acidity, mineral uptake and pH during the maturation of grapes. It can also be used to estimate the tartrate to malate ratio in the juice, an important consideration in the selection of a deacidification procedure for juices that are high in total and titratable acidity.