Code International des pratiques œnologiques

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Control of the sugar content of the harvested grapes

II.1.10 Control of the sugar content of the harvested grapes

Definition:

Increase of the sugar content in the grape crop, that is to say in the harvested grapes.

Objective:

To increase the sugar content of the raw materials used.

Prescriptions:

The objective can be achieved by the use of one or more of the following practices:

a)        Natural raisining: Operation consisting of exposing grape bunches on straw, racks and other supports or suspending them for the appropriate time to reach the desired sugar content:

  • In the sun
  • In the open or a naturally ventilated enclosure.

b)       Raisining by physical treatment (**)[1]: Operation involving a forced artificial ventilation of grapes at 35°-40°C for the appropriate time to reach the desired sugar content.

c)        Selective sorting of grapes: Operation consisting of selecting the most ripe bunches, parts of bunches and grape berries to obtain the must from them: manual sorting during or after the harvest.

d)       Cryoselection in the vineyard without recourse to physical procedures: Prescription consisting of letting grapes partially freeze on the vine, then pressing them at low temperatures to produce a must with a higher sugar content.

e)       Cryoselection by physical procedures Prescription consisting of partially freezing grapes in a cold room, then pressing at a low temperature in order to produce a must with a higher sugar content

Recommendation of OIV:

Admitted


[1] ** indicate that the production conditions are being studied