azeotrope, from the Greek ‘to boil unchanged’, a mixture of liquid chemicals which has a boiling point either higher or lower than any one of its components. The principal volatile components of wine tend to form azeotropes of two, three, or more components. Water, ethanol, volatile organic acids, aldehydes, esters, acetals, and ketones, many of them powerfully aromatic, are among the azeotrope components in wines. The multiplicity of volatile compounds present in wine and our lack of detailed knowledge of all of the azeotropes possible makes it difficult to predict the composition of distillates (which depend on the varied boiling points of components).
