Acids, Grapes, Wines and People

¹ Department of Viticulture and Enology, University of California, Davis.

Differences in acidity of grapes result in different types of fermentation and qualities of wine. The differences are caused by variations: a} in the ratio of tartaric to malic acids, b) between varieties, and c) in climatic conditions. The per cent malate and the per cent of the titratable acidity due to malates is greater the cooler the region. The pH is lower in grapes from cool regions and seasons. Classification of grape varieties on the basis of sugar and acid content and on the ratio of the two is suggested.

Human beings respond in various ways to acids. In fact, they are quite as variable in response as the variability of acids in the raw material, some preferring high acidity and others low. These differences appear to be rather specific.