International Code of Oenological Practices

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Concentration of must by reverse osmosis

II. Concentration

Definition :

Process consisting of concentrating must by elimination of part of the water through specific membranes under the action of a pressure greater than the osmotic pressure of the must.

Objective :


To obtain an enrichment of the must, especially in sugars.


Prescriptions :


a)        The concentration can be performed on all or part of the must.

b)       The concentration shall not be undertaken to reduce the initial volume of the must by more than 20% nor to increase the initial potential alcohol content of the must by more than 2% (vol.).

c)        Since this procedure entails a concentration of all must constituents, its application shall be limited to musts where its use is justified.  It should not be used to modify the type of wine produced.

d)       The procedure shall be conducted under the responsibility of an oenologist or a specialist technician.

e)       The membranes used shall comply with the prescriptions of the International Oenological Codex.


Recommendation of OIV