International Code of Oenological Practices

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Chemical de-acidification

II. Chemical de-acidification

Classification :

  • Potassium L(+) tartrate: processing aid
  • Calcium carbonate: processing aid
  • Potassium hydrogen carbonate: processing aid


Decrease of the acidity and the actual acidity (increase of the pH) by addition of neutral potassium tartrate, potassium hydrogen carbonate or calcium carbonate containing possibly small quantities of the calcium double salt of L(+) tartaric and L(-) malic acids.

Objectives :

a)       See II. ‘De-acidification’

b)       To favour biological de-acidification.

Prescriptions :

a)        The wine produced from a de-acidified must shall contain at least 1 g/l tartaric acid;

b)       The process of the formation of the double salt (neutral calcium salts of tartaric and malic acids) should be applied in the case of musts very rich in malic acid for which precipitation of the tartaric acid alone does not provide a satisfactory reduction of the titratable acidity,

c)        The aim of chemical de-acidification shall not be to conceal fraud,

d)       Chemical de-acidification and chemical acidification are mutually exclusive.

e)       The products added shall comply with the prescriptions of the International Oenological Codex.

Recommendation of OIV: