RESOLUTION OIV-OENO 546-2016

USE OF NON-SACCHAROMYCES YEASTS – REVISION OF RELEVANT FILES OF THE INTERNATIONAL CODE OF OENOLOGICAL PRACTICES

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 increased use of non-Saccharomyces cerevisiae yeasts in the oenological wine making process,

CONSIDERING the works of the “Microbiology” Expert Group, and in particular of the working group who reviewed the use of the word “Saccharomyces” yeasts in the International Code of Oenological Practices,

DECIDES, following a proposal made by Commission II “Oenology”, to review some files of the International Code of Oenological Practices, adapting them through the use of the word “yeasts” to replace the term “Saccharomyces”,

DECIDES to remove file 2.1.3.2.3.2 De-acidification by Schizosaccharomyces,

DECIDES to modify files 2.1.3.1.2 Microbiological acidification, 2.1.3.1.2.1 Acidification by Saccharomyces, 2.1.3.2.3 Microbiological de-acidification , 2.1.3.2.3.1 De-acidification by Saccharomyces and 2.3.1 Inoculation with yeasts as follows:

• In part 2 (musts), file 2.1.3.1.2 Microbiological acidification:

in the paragraph Recommendation of the OIV, replace the word “Saccharomyces” with “yeasts (Saccharomyces and non-Saccharomyces)”,

in the paragraph under Prescriptions: “In order to achieve this objective, microbiological acidification by yeasts may be carried out, either spontaneously or by inoculation of selected strains.” (The struck-through text is deleted).

• In part 2 (musts), file 2.1.3.1.2.1 Acidification by Saccharomyces:

in the title of the file, replace the word “Saccharomyces” with “yeasts”,

in the paragraph under Definition, replace the phrase “Saccharomyces Sp. strain type” with “yeasts (Saccharomyces and non-Saccharomyces)”.

• In part 2 (musts), file 2.1.3.2.3 Microbiological de-acidification (except for sub-file 2.1.3.2.3.3. De-acidification by lactic acid bacteria):

In the title of the file: replace “Microbiological de-acidification” with “Microbiological de-acidification by addition of yeasts (Saccharomyces and non-Saccharomyces)”,

in the paragraph under Recommendation of the OIV, under See sheets, replace the phrases “De-acidification by Saccharomyces and De-acidification by Schizosaccharomyces” with the phrase “De-acidification by yeasts (Saccharomyces and non-Saccharomyces)”,

in the paragraph under Prescriptions: “In order to achieve this objective, microbiological de-acidification by yeasts may be carried out either spontaneously or by inoculation of selected strains.” (The struck-out text is deleted).

• In part 2 (musts), file 2.1.3.2.3.1 De-acidification by Saccharomyces:

in the title of the file, replace the word “Saccharomyces” with “yeasts”,

in the paragraph under Definition, replace the phrase “Saccharomyces-type yeast” with “selected yeasts (Saccharomyces and non-Saccharomyces)”,

in the paragraph under Objectives, point b) is replaced with the phrase “To obtain a partial or total breakdown of malic acid by a biological pathway” (The part in italics is added),

in the paragraph under Prescriptions, point b) is replaced with the phrase “The objective under b) can be achieved during alcoholic fermentation using yeasts doted with alcohol forming power in pure culture or in succession using selected Saccharomyces or non-Saccharomyces strains. Strains of Saccharomyces genus are known for their partial breakdown capabilities. Strains of Schizosaccharomyces pombe are known for their total malic acid breakdown capabilities.” (The part in italics is added and the part struck out is deleted),

in the paragraph under Prescriptions, point c) is added:

c) The use of Schizosaccharomyces yeasts has shown its efficiency for obtaining a rapid breakdown, 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.

in the paragraph under Prescriptions, point c): “Yeasts must comply with the prescriptions of the International Oenological Codex” changes to point d).

• In part 2 (musts), file 2.3.1  Inoculation with yeasts:

In the paragraph Objectives, these points are added:

d) To change the wine acidity by synthesis or breakdown of organic acids.

e) To produce less volatile acidity, especially in the case of musts with high sugar levels.

f) To impact on the wine’s sensorial properties (aromas, mouthfeel).

In the paragraph under Prescriptions, point a) is changed to:

a) Use the yeast or mixture of yeasts appropriate for the objective pursued.

and these points are added:

b) In the case of non-Saccharomyces, the addition occurs before or at the same time as for the Saccharomyces.

c) The commercial starters added may be pure cultures or blends of Saccharomyces strains and non-Saccharomyces strains.

in the paragraph under Prescriptions, point d (ex b), the term “active, dry yeasts” is replaced by “selected yeasts (Saccharomyces and non-Saccharomyces)”.