International Code of Oenological Practices

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De-acidification using an electromembrane process

II. De-acidification using an electromembrane process


Physical method of ionic extraction from the must under the action of an electric field using permeable membranes with anions on the one part and bipolar membranes on the other. The combination of permeable membranes with anions and bipolar membranes is used to manage a reduction in titratable acidity and the actual acidity (increase in the pH).


a)        Correct excess natural acidity caused by climate conditions in the wine region by reducing titratable acidity and actual acidity (increase in the pH)

b)       Develop balanced wines in terms of taste

c)        Promote a smooth wine maturing operation


a)        Refer to the general file on separative techniques used in the processing of musts and wines and the file on the application of membrane techniques to musts.

b)       De-acidification using an electromembrane process should not be intended to hide a fault.

c)        The anionic membranes must be composed in such a way that they only allow the extraction of anions and in particular the organic acids from the must.

d)       The bipolar membranes are impermeable to anions and cations in the must.

e)       The wine from a de-acidified must should contain at least 1g/L-1 of tartaric acid.

f)         De-acidification by membrane process and acidification are mutually exclusive;

g)        An oenologist or qualified technician will be responsible for implementing the process.

h)       The membranes used must comply with the prescriptions contained in the “International Oenological Codex”

OIV recommendation: