International Code of Oenological Practices

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Microbiological de-acidification by lactic acid bacteria

II. Microbiological de-acidification

Definition :

Reduction of the titratable acidity and the actual acidity (increase of the pH) by malolactic fermentation.

Objective :

To produce wines :

a)       See II.3.1.2 ‘De-acidification’

b)       Biologically more stable.

Prescriptions :

To achieve the objectives, the microbiological de-acidification by lactic acid bacteria can be performed either in a spontaneous manner or by inoculation of selected strains.

a)        The sulphur dioxide content should be limited, lactic acid bacteria being very sensitive to the presence of this compound,

b)       It is desirable that malolactic fermentation takes place at the end of the alcoholic fermentation, to avoid bacterial degradation of sugars,

c)        The wine in which malolactic fermentation is to occur should be maintained at a temperature of approximately 18°C.

d)       Where selected cultures of lactic acid bacteria are used, these shall comply with the prescriptions of the International Oenological Codex

Recommendation of OIV :