II.1.8 Maceration after heating the harvested grapes

Definition:

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.

Objectives:

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

b)       Prevention of enzymatic processes.

Prescription:

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:

Admitted