International Code of Oenological Practices

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Inoculation with yeasts

II.2.3.1 Inoculation with yeasts

Definition :

Inoculation of a must, before or during its fermentation, with the help of a starter inoculum prepared either from indigenous yeasts or from selected yeasts.

Objectives :

a)        To initiate, regulate and accelerate fermentation, especially in the case of vinifications, which are proceeding too slowly.

b)       To re-activate an interrupted fermentation.

c)        To facilitate the depletion of glucose and fructose.

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).

Prescriptions :

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

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.

d)       Where active, selected yeasts (Saccharomyces and non-Saccharomyces) are used, these shall comply with the prescriptions of the International Oenological Codex.

Recommendation of OIV: