International Code of Oenological Practices

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Maceration after heating the harvested grapes

II.1.8 Maceration after heating the harvested grapes


Process of heating whole, crushed or de-stemmed grapes, before the start of fermentation, to temperatures chosen according to the desired goal, and maintaining them at these temperatures for a certain period of time.


a)        More rapid and more complete extraction of colour and other substances contained in skins.

b)       Prevention of enzymatic processes.


a)        The must may ferment either in contact with or in the absence of solids.

b)       The process must not lead either to a concentration, or to a dilution. Consequently:

  • Excess heating is to be avoided,
  • Heating by injection of steam is forbidden.


Recommendation of OIV: