Inactivated Yeasts

Inactivated yeasts are added to juice and/or wine to facilitate successful fermentation which doesn’t end prior to the intended point of dryness. Inactivated yeasts are permitted for use in grape wine in over 25 countries worldwide. 

Inactivated yeasts are used as nutrients for yeasts at the beginning of and during alcoholic fermentation, and also to encourage the rehydration of active dry yeasts. They can help to reduce the level of Ochratoxin A in the steps for wine maturing and clarification operations. They are produced by the biomass of Saccharomyces spp., inactivated by heat and/or by modification of the pH. They may have undergone the beginnings of a natural autolysis through the action of the endogenous enzymes. 

Production techniques are those conventionally used for the biomass of yeasts. In the process, there is no addition of antibiotics or of compounds other than those needed to grow the yeast. When inactivated yeasts come from genetically modified yeasts, they must be authorised for use beforehand by the relevant authorities. 

In solid form they are usually available as granules, powder or flakes, of light to tan yellow in colour, with an odour characteristic of yeast. Inactivated yeasts are partially soluble in water, the insoluble part being greater than or equal to 60% m/m of the dry matter. For further substance information, please see the OIV’s International Oenological Codex.