Originally discovered by French scientist Michel Flanzy, and later perfected by Beaujolais négociant, taster and chemist Jules Chauvet, carbonic maceration is a winemaking process used to create a style of red wine that is lively, fresh and fruity on the nose; and soft and light on the palate.
Carbonic maceration needs two things: whole bunches of grapes and a fermentation tank filled with carbon dioxide and heated to around 30 degrees Celsius.
Due to the lack of oxygen and the presence of carbon dioxide, metabolic changes occur inside the grape during the first fermentation. Under the skin, in the flesh of the grape, the structure is attacked by the grape’s own enzymes, which release a small amount of alcohol. Essentially the grape is working from the inside out as opposed to from the outside in. This is called ‘intracellular fermentation’.
The grape bunches can stay in the first vat for up to 15 days to macerate before the second fermentation takes place. Carbonic maceration results in softer skins and tannins because of the higher temperatures in the carbon dioxide vat.
The semi-soft juice and pulp are pressed and transferred to a cooler second tank with a temperature of about 20 degrees to allow the naturally occurring yeast to ferment the fruit further—with or without the addition of more yeast. This part of the process is extracellular, because it happens outside the cell structure.
This type of wine is closely associated with the Beaujolais area of France, most notably Beaujolais Nouveau These red wines are made from the Gamay grape and drunk very young, only fermenting for a matter of weeks before being enjoyed in mid-November.
If you are familiar with Beaujolais Nouveau, you will know the fruity bubble-gum-esque notes that dance around on the tongue with a certain playfulness and sense of youth. These are the distinct flavours of the carbonic maceration winemaking method.