The vinification of black grapes into red wine follows several crucial steps. First, the grapes are destemmed: the stalk (the woody support of the bunch) is removed. The grapes are then crushed to release the pulp and juice and they are placed in maceration vats. Alcoholic fermentation then begins, lasting on average from 4 to 10 days. At the end of fermentation stage, the wine is separated from the marc (the solid parts of the grape) by gravity: this is the free run wine, while the pressed marc gives the so-called press wine. These two wines are blended either immediately or after some aging in the barrel. A second fermentation is then triggered: this malolactic fermentation reduces the acidity of the wine and stabilises it naturally.