RESOLUTION OIV-OENO 738-2025

TREATMENT OF MUSTS WITH FUMARIC ACID FOR MICROBIOLOGICAL CONTROL

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,

CONSIDERING the work of the “Technology” Expert Group,

CONSIDERING that fumaric acid acts as a powerful inhibitor of malolactic fermentation (MLF) and behaves as an effective bactericide substance against lactic acid bacteria at low doses,

CONSIDERING that in the context of global warming, the preservation of malic acidity may prove useful in certain types of wines,

CONSIDERING that the control of MLF and the inhibition of lactic acid bacteria may help to reduce SO₂ content during vinification,

DECIDES, on the proposal of Commission II “Oenology”, to introduce the following oenological practice into chapter 2, part II, of the International Code of Oenological Practices:

Part II

Chapter 2: Musts

Sheet 2.1.28

TITLE: Treatment of musts with fumaric acid for microbiological regulation

Classification:

Fumaric acid: additive

Definition:

Treatment of musts to inhibit and delay the development of lactic acid bacteria.

Objectives:

1. Control the growth and activity of lactic acid bacteria responsible for initiating malolactic fermentation in must and, where applicable, spoilage by lactic acid bacteria;
2. Reduce the dose of sulphur dioxide;
3. Preserve malic acidity.

Prescriptions:

1. The dose used can be up to 0.8 g/L;
2. In certain specific situations, such as sluggish fermentations, the addition of fumaric acid can have a negative impact on the kinetics of alcoholic fermentation;
3. The fumaric acid used must comply with the prescriptions of the International Oenological Codex.

OIV recommendation:

Admitted.