RESOLUTION OENO 1/2003

DE-ACIDIFICATION BY SCHIZOSACCHAROMYCES

THE GENERAL ASSEMBLY,

AFTER HAVING been informed of the works of the experts group “Wine Microbiology” and “International Code of Oenological Practices”,

DECIDES:

UPON PROPOSAL of Commission II “Oenology” to replace in the “International Code of Oenological Practices” the sheet 2.2.3.2 by the following sheet:

PART II

Chapter 2: Musts

2.2.3.2. De-acidification by Schizosaccharomyces

Definition:

Decrease in titratable acidity and real acidity (increase in pH) by the use of Schizosaccharomyces yeasts.

Objective:

Degrade L-malic acid in order to make balanced wine in terms of gustatory quality.

NOTE:

The experiments so far on the use of Schizosaccharomyces yeasts have shown their efficiency for obtaining a rapid degradation, whether partial or complete, of L-malic acid in musts and wines. Due to the great decrease of titratable acidity and the concentration of hydrogen ions, induced by the activity of these yeasts, their development can be undesirable for certain wines. So precautions should be taken to avoid contamination of the vats for which the development of these yeasts is undesirable. Their easy sporulation and their development may pose serious problems for the contamination of musts from the same winery or even from an entire wine growing area where they are considered undesirable in terms of acidity conservation or because of the risk of seriously modifying the sensory quality of the wine.

Prescription

Schizosaccharomyces yeasts should comply with the prescriptions of the International Oenological Codex.

Recommendation of the OIV:

Admitted.