Maceration, while essential for a wine to improve with age, must be carefully monitored. If it is too long, it can lead to herbaceous aromas or hard and bitter tannins, depending on the situation.
For it to be beneficial, the raw material must be ripe and healthy. A prolonged maceration of grapes that are slightly underripe is not necessarily desirable since there is a higher risk of extracting vegetal aromatic compounds or green tannins.
Furthermore, the extraction that took place during alcoholic fermentation must also be taken into account. If this extraction was intensive, there is little point in prolonging the maceration period longer than necessary.
Time is an important factor in obtaining a good maceration, but so is vat temperature, which will modify the extraction of phenolic compounds. Traditionally, maceration is carried out at room temperature (around 20°C) and the tank is left to cool down on its own at the end of the fermentation. However, it is possible to hold the post-fermentation maceration at a warm temperature for several days in order to extract more compounds and increase roundness and sweetness in some cases.
As an example, vatting time (from the moment the wine is put in the vat to the end of the post-fermentation maceration) usually lasts between 18 to 24 days for a Cabernet Sauvignon. For some varieties, it can last up to four or five weeks.