Rev. Rul. 63-69

The use of cation exchange resin `Duolite C-20,' regenerated with mineral acid, to remove undesirable metallic substances from wine is considered as being consistent with good commercial practice, subject to the following limitations: (1) the regenerated column must be washed with ion-free water until the pH of the effluent water is the same as that of the influent water; (2) the inorganic anions may not be increased more than 10 mg. per liter; (3) the potassium content may not be reduced below 300 ppm.; and (4) the pH may not be reduced below 3.0 pH units.

Winemakers desiring to use this resin in the treatment of wine may obtain approval of the Assistant Regional Commissioners, Alcohol and Tobacco Tax, by filing a notice pursuant to the provisions of section 240.1052 of the Wine Regulations.