The chemistry of chaptalization

Abstract Within the European Community — and, indeed, among all the major wine-producing countries —increasing attention is being paid to the enforcement of wine quality control regulations. For this purpose highly sophisticated techniques have been developed, of which the most powerful is based on isotope fractionation. Isotopic ‘fingerprinting’ not only makes it possible to estimate precisely the degree of chaptalization or dilution with water, but the region from which a wine has come and even the year in which it was made.