The fundamental relationships that exist between the total acidity (the equivalence of the acid anions as measured by spectrophotometric or chromatographic methods), the titratable acidity (as measured by titration to a pH endpoint with a strong base) and pH in wines are elucidated for the first time. The acid and mineral analyses of 21 European wines are used to confirm the first of these relationships. A possible mechanism for the relationship is suggested. The values of titratable acidity and pH predicted from the operation of this mechanism are compared with the reported values for a number of wines. Acid and mineral analyses of Californian wines are used to confirm the general nature of the relationships.