prefermentation

Prefermentation is a winemaking technique in which a stage of skin contact occurs before the onset of alcoholic fermentation. The goal is to extract color, aroma compounds, and tannins from grape skins to improve the wine’s structure and balance, especially in red wines. The term encompasses practices such as pre-fermentation maceration and cold soaking (cold maceration).

Typically, prefermentation involves crushing the grapes and allowing the must to remain in contact with skins at low temperatures, commonly around 5 to 12 degrees Celsius, for a period ranging from 12 to 72 hours, though durations vary by style and vintage. After this period, fermentation is initiated by adding yeast, with fermentation proceeding in the usual manner. Temperature control and sanitation are important during this stage to minimize spoilage, and some winemakers use sulfur dioxide to modulate microbial activity or oxidation during prefermentation.

The expected outcomes include increased color extraction, enhanced aroma precursors, and a potentially smoother tannin profile. However, risks exist, such as oxidation or microbial spoilage if conditions are not carefully managed, as well as the possibility of over-extraction if duration or temperature are not properly controlled. In white wines and rosés, brief skin contact before fermentation is used in some styles to capture aromatic components, though this is less common than in red winemaking.

In practice, prefermentation is one approach within a broader range of skin-contact techniques used to influence color, aroma, and mouthfeel, including methods that occur after fermentation.