Chaptalization: The addition of sugar to juice before and/or during fermentation, used to boost sugar levels in underripe grapes and alcohol levels in the subsequent wines. Common in northern European countries, where the cold climates may keep grapes from ripening, but forbidden in southern Europe (including southern France and all of Italy) and California.
Acidification: The addition of acid to wine by a winemaker. The goal is to balance the wine’s soft components (sugar, alcohol and fruit). It is legal in some areas—such as Bordeaux, Burgundy, Australia and California—to correct deficient acidity by adding acid. When overdone, acidity leads to unusually sharp, acidic wines. It is illegal in Bordeaux and Burgundy to both chaptalize (add sugar to) and acidify a wine.