Maceration describes a generally applicable physical process in which various ingredients are dissolved out of a body by remaining in a liquid.
Applied to winemaking, this means that the color, but also the fruit flavor and tannins, are extracted from the grape skin and pulp, especially during fermentation. The juice of the crushed grapes serves as a solvent. The result is called macerate.
In red wine production, maceration is staggered over time. During alcoholic fermentation, i.e. when the sugar in the grapes is converted into alcohol, the mash, consisting of grape skins, grape seeds and the must, is left to stand for several days. During this time, the colorants in particular dissolve, giving the must the red color of the future red wine.
When the sugar is then converted into alcohol, it also serves as a solvent, which releases various phenol-like substances, including tannins, from the solid components of the mash. The tannins, in turn, vary in quality and have a decisive influence on the subsequent quality of the wine.
In order for maceration to be successful, it is necessary for the grape skins to remain in contact with the alcoholic must as a solvent as often and for as long as possible. However, as the solid components of the wine always settle on the surface of the fermentation tank – also known as the cap – the cellar master is required to ensure contact. This can be done by pumping the must to the top, where it then flows over the solid components, also known as remontage. Or he can use the so-called pigeage, in which the entire cap is pressed downwards into the must.