Some winemaking details Fermentations can be somewhat controlled by temperature modification. This gives rise the popularity of stainless steel vats with refrigeration jackets for cooling, as normal fermentation proceeds with liberation of heat. Wines are not often naturally clear. An alternative procedure for fermentation is carbonic maceration, in which red grapes bunches are left in their skins to start fermentation spontaneously, beginning with the grapes' own enzymes. A CO2 saturated atmosphere is maintained.
Fermentation is completed by yeasts.
The general name for sugar enhancement is chaptalization, after Chaptal, Napoleon's minister of agriculture, who wrote a treatise on wine production. It is made in a variety of styles with variable residual sugar, so it's best to ask if you are looking for one that is specifically dry or off-dry. This leaves a fresh aftertaste not unlike grapefruit that many people enjoy. An excellent muscat dessert wine from the Rhone in France is Muscat de Beaumes de Venisse. Varietal labeling, almost unheard of in Italy 20 years ago, is now quite the fashion in vini da tavola.