RESOLUTION OIV-OENO 545A-2016

UPDATE TO THE FILE ON OXYGENATION FOR MUSTS

The General Assembly,

CONSIDERING Article 2, paragraph 2 iv of the Agreement of 3 April 2001 establishing the International Organisation of Vine and Wine,

CONSIDERING the work of the "Technology" Expert Group during its March 2014 session,

DECIDES, at the proposal of Commission II "Oenology", to delete file 2.3.5 Aeration (16/70) and replace file 2.1.1 in the International Code of Oenological Practices as follows:

Title: Oxygenation of musts

Definition

Addition of oxygen or air to must

The Objective part shall be replaced with:

Objectives:

1. To accelerate the oxidation process in musts in white or rosé winemaking with the aim of provoking browning reactions in phenolic compounds, which are formed by polymerisation, then precipitate and are removed during clarification of musts, to improve the stability of wines in relation to oxidation. This practice, which provides for the addition of high levels of oxygen to musts, equivalent to several saturations, is called “hyperoxygenation”;
2. to contribute to the reduction of aromas compounds related to vegetal sensory character and the disappearance of reductive aromas;
3. to ensure alcoholic fermentation occurs smoothly and to avoid stuck fermentations.

The Prescription part shall be replaced with:

Prescriptions:

1. In the case of reduction of the level of phenolic compounds involved in browning phenomena, oxygen should be added before clarification of must;
2. in the case of management of fermentation kinetics, the addition of oxygen at the recommended dose of 5-10 mg·L-1 is sufficient provided that this is carried out at the end of the yeast growth phase, namely after the reduction of the sugar concentration of the must by around 50 g·L-1;
3. the aim of oxygenation should not be a reduction in sulphite of musts containing excess sulphur dioxide.