Rev. Rul. 65-252

The use of cation exchange resins Amberlite IR-120-H, Amberlite IR-120, Amberlite IRC-50, Amberlite XE-89, Duolite C-3, Duolite C-25, Permutit Q Spec 157, and SAF, regenerated with mineral acid, to remove undersirable 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 ionfree 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 these resins in the treatent of wine may obtain approval of the Assistant Regional Commissioner, Alcohol and Tobacco Tax, by filing a notice pursuant to the provisions of 26 CFR 240.1052.