The quantity of residual sugar in a wine determines whether it is classified as sweet or dry. A wine's acidity, tannins, alcohol content, and frequently its fruitiness all affect how sweet it tastes on the palate. Michigan's sweet wines are a result of the state's winemakers' efforts to strike a delicate balance between sugar, acidity, and alcohol. When a wine is well-balanced, you won't taste any of these characteristics. Acid levels in grapes increase as the fruit matures on the vine, and as the grapes ripen, the acidity is processed and the sugar content increases. Warmth aids the metabolism. Because of the cold temperature, Michigan's grapes have higher amounts of acid, and less of that acid is converted than it would be in a more warm climate (such as, California). As a result, have a little more sugar to achieve the desired balance. Even though it doesn't taste sweet all the time, the sugar cuts down on any acidity that would otherwise have been present.