RESOLUTION OIV-OENO 616-2019

TREATMENT OF CRUSHED GRAPES WITH ULTRASOUND TO PROMOTE THE EXTRACTION OF THEIR COMPOUNDS

THE GENERAL ASSEMBLY,

IN VIEW of article 2, paragraph 2 ii of the Agreement of 3 April 2001 establishing the International Organisation of Vine and Wine,

ON THE PROPOSAL of the “Technology” expert group,

DECIDES, on the proposal of Commission II "Oenology", to introduce the following oenological treatment into part II of the International Code of Oenological Practices:

PART II

1. GRAPES

TITLE: TREATMENT OF CRUSHED GRAPES WITH ULTRASOUND TO PROMOTE THE EXTRACTION OF THEIR COMPOUNDS

Definition:

Usage of ultrasound for a rapid extraction of grape compounds

Aim:

To stimulate extraction of grape compounds during pre-fermentation maceration, after destemming and crushing, by using of ultrasound, with the following aims:

• To obtain a must with a higher concentration of phenolic compounds and other  grape compounds
• To obtain wines with an adequate and stable phenolic composition, reducing the maceration time compared to a traditional process
• To limit the release of tannins present in the seeds (since maceration time is decreased), mainly when the treated grapes have a low phenolic maturation
• To accelerate the grape processing

Prescriptions:

1. The treatment must be carried out on destemmed and crushed grapes in order to increase the performance of the treatment
2. In order to avoid a temperature increase in the bulk of crushed grapes this treatment should be done with the bulk in movement
3. To boost an efficient cavitation process, the solid/liquid proportion in the bulk of crushed grapes must be adequate.

OIV Recommendation:

Accepted.