# Commission Delegated Regulation (EU) 2019/934 of 12 March 2019 supplementing Regulation (EU) No 1308/2013 of the European Parliament and of the Council as regards wine-growing areas where the alcoholic strength may be increased, authorised oenological practices and restrictions applicable to the production and conservation of grapevine products, the minimum percentage of alcohol for by-products and their disposal, and publication of OIV files, Division 2: MEMBRANE UTILISATION REQUIREMENTS

Extent: E+W+S+N.I.

The membrane pair is formulated so that the following conditions are met:
the pH reduction of the wine is to be no more than 0,3 pH units,
the volatile acidity reduction is to be less than 0,12 g/l (2 meq expressed as acetic acid),
treatment must not affect the non-ionic constituents of the wine, in particular polyphenols and polysaccharides,
diffusion of small molecules such as ethanol is to be reduced and must not cause a reduction in alcoholic strength of more than 0,1 % vol.,
the membranes must be conserved and cleaned by approved methods with substances authorised for use in the preparation of foodstuffs,
the membranes are marked so that alternation in the stack can be checked,
the equipment is to be run using a command and control mechanism that will take account of the particular instability of each wine so as to eliminate only the supersaturation of potassium hydrogen tartrate and calcium salts,
the treatment is to be carried out under the responsibility of an oenologist or qualified technician.
The treatment is to be recorded in the register referred to in Article 147(2) of Regulation (EU) No 1308/2013.

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Source: https://www.legislation.gov.uk/eur/2019/934/annex/I/division/5/division/1/division/2 (the official version)
Page: https://openlegislation.uk/eu-regulation-2019-934/annex-I/division-5/division-1/division-2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.