From the north of the Bourgogne region to the south, depending on the characteristics of the vintage, vinification of red wines can vary greatly. For example, some winegrowers destalk their grapes, while others vinify in whole bunches. The varietal plays a key role, too. Pinot Noir, which is particularly delicate, requires a more careful approach than any other grape.
Vinification of red wine starts with alcoholic fermentation, a process during which the grape juice turns into wine. Unlike with white wines which are pressed on arrival in the winery, grapes for red wines, either crushed or in whole bunches, are placed in vats to macerate. The juice is clear to start with and requires contact with the skins and pips to bring color and tannins to the wine. During this maceration process, the alcoholic fermentation begins, either naturally or sometimes triggered with the addition of yeasts.
Each day, the cap of skin and pips is broken up and pushed down into the juice to help the development of color and tannins. The process is known as pigeage and used to be done with the feet. Nowadays, a special tool is used to protect the raw material.
When fermentation is complete, the wine is pressed and then placed in vats or barrels for ageing.
During the ageing process, the red wines undergo a second malolactic fermentation, during which the malic acid in the wine turns to lactic acid, making the wines smoother.
Transformation of the must sugars into alcohol by fermentation yeasts: Saccharomyces cerevisiae. These can be yeasts that are selected and added to the must in order to control fermentation start-up or yeasts naturally present on the grape and in the tank room (indigenous yeasts).
This reaction is accompanied by a release of carbon dioxide. It can take place in barrels or tanks. When alcoholic fermentation is completed the wine is racked, i.e. it is moved to a different container.