International Code of Oenological Practices

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Reduction of the sugar content in musts Fining using yeast protein extracts

II.2.1.25 Reduction of the sugar content in musts Fining using yeast proten extracts

Classification :

  • Yeast protein extracts: processing aid


Operation that consists in extracting a certain quantity of sugar from grape must.


a)        Produce musts with lowered sugar conte

b)       Develop a wine with reduced ethanol content by decreasing the sugar content of the must.


a)        Refer to the general sheet concerning must and wine treatments with separation techniques used in the treatment of musts (sheet 2.0) and the sheet concerning the application of membrane techniques used for musts (sheet 2.0.0),

b)       The objectives may be met with various techniques:

  • membrane coupling
  • other methods**[1]

c)        The process entails a reduction in volume dependant on the quantity and sugar content of the sugar solution extracted from the initial must.

d)       The processes must enable to preserve the contents in must components other than sugar.

e)       The reduction of the sugar content in musts excludes the dealcoholisation of the wines from which they originate

f)         This practice must not be used in conjunction with the enrichment techniques for musts and wines

g)        The reduction of the sugar content is limited because of the significant reduction of volume and the results of the separation techniques used.

h)       For objective b) the end product must comply with the definition of wine.

Recommendation of the OIV:

Refer to the sheets concerning the practices and treatments mentioned above.

[1] ** indicate that the production conditions are being studied