Carbonic Maceration: Most frequently associated with Beaujolais, this is a method of producing light-bodied, fresh and fruity red wines. Instead of crushing the grapes and releasing the juices to be fermented by yeasts, whole grape bunches are placed in a tank and the oxygen is displaced by carbon dioxide. Fermentation starts on an intracellular level inside the berry, producing some alcohol as well as fruity aromatics. In practice, the weight of the grapes on the top crushes the grapes on the bottom and yeasts ferment the juice; the wine is partly a product of carbonic maceration and partly of traditional yeast fermentation.
Maceration: This process, used primarily in making red wine, involves steeping grape skins and solids in wine after fermentation, when alcohol acts as a solvent to extract color, tannins and aroma from the skins (aided by heat, the amount of skin contact and time). Cold maceration (steeping when the must is not heated), takes place before fermentation.