maceration, ancient word for steeping a material in liquid with or without a kneading action to separate the softened parts of the material from the harder ones. This important process in red winemaking involves extraction of the phenolics (tannins, colouring materials, or anthocyanins, other glycosides, including flavour precursors, and non-glycosylated flavour compounds) from the grape skins, seeds, and stem fragments into the juice or new wine. Some maceration inevitably takes place in the fermentation vessel. It is governed by temperature, contact between the solids and liquid and the degree of agitation, time, and by the composition of the extracting liquid, in this case the grape juice as it becomes wine. Although everyday red wines are made simply by a rapid fermentation lasting just two or three days, many winemakers encourage an additional maceration period after fermentation has been completed, particularly for long-lived wines such as red bordeaux. If fermentation is slow to start, possibly due to the low temperature of the grapes and/or the use of ambient yeast, the winemaker may take advantage of the ‘accidental maceration’ that results.
