Cold soak, also called pre-fermentation maceration, is the practice of holding crushed or destemmed red grapes at a low temperature before alcoholic fermentation begins. The aim is to encourage extraction of colour and some aroma compounds from the skins while limiting early alcohol-driven tannin extraction. The method is used selectively and requires careful temperature and microbial control.
Crushed or destemmed grapes are held in a fermentation vessel at a controlled low temperature for a period determined by the grape, fruit condition and desired style. The must is kept cold enough to slow or delay yeast fermentation, but it must be managed to prevent spoilage organisms from becoming active. After the soak, the must is allowed to warm and alcoholic fermentation begins or is initiated.
Cold soaking may increase early colour extraction and influence the aromatic profile and texture of the finished red wine. The result varies with grape variety, skin condition, temperature, duration and subsequent fermentation. It does not guarantee a softer wine or higher colour intensity.
Cold soak takes place before alcoholic fermentation. Extended maceration continues skin contact after fermentation has finished or nearly finished. Both involve contact between juice or wine and grape solids, but they occur at different stages and extract different compounds.
Example: a Pinot Noir producer may use a short, controlled cold soak before fermentation to influence colour and fruit expression.
Chef’s note: cold soaking is not simply refrigerating grapes. It is a controlled cellar operation requiring temperature, hygiene and microbial management.
This term is one of hundreds covered in depth across OCS courses, learning paths, and 1-on-1 coaching with Chef Eric.
