RESOLUTION OIV-OENO 658-2023

METALS REMOVAL FROM AGED WINE VINEGARS BY CHELATING RESINS OF STYRENE-DIVINYLBENZENE WITH IMINODIACETIC FUNCTIONAL GROUP

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,

UPON THE PROPOSAL of the “Technology” group of experts,

DECIDES following a proposal made by Commission II “Oenology”, to introduce into Part II, Chapter 6 of the International Code of Oenological Practices the following oenological treatment:

METALS REMOVAL FROM AGED WINE VINEGARS BY CHELATING RESINS OF STYRENE-DIVINYLBENZENE WITH IMINODIACETIC FUNCTIONAL GROUP

Definition:

Physical partial extraction of metal ions from aged wine vinegars by chelating resins.

Objective:

Reduce the concentrations of metal ions (iron and copper) to avoid stability problems in aged wine vinegars (aged in barrels for a minimum of two years).

Prescriptions :

1. the treatment will be performed using chelating resins with iminodiacetic active group regenerated in the acid cycle;
2. the treatment must be limited to the elimination of excess metal ions;
3. the treatment will only be used on aged wine vinegars to remove metals acquired (enriched) during the ageing process;
4. the treatment will preferably be carried out by percolation. In this case, the duration of the cycle must be controlled to avoid desorption of fixed ion metals;
5. as an alternative, the resin could be directly introduced into the tank of wine vinegar (for 12 to 48 hours), in the quantities required, then separated by filtration;
6. disposal of regeneration water must be carried out in an environmentally friendly manner;
7. all operations will be placed under the responsibility of an oenologist or a qualified technician;
8. the resins must comply with the prescriptions of the International Oenological Codex.

Recommendation of the OIV:

Accepted