Rev. Rul. 65-278

The Internal Revenue Service has been asked whether a clarifying agent composed of Bentonite, Activated Carbon, and Copper Sulfate may be used in the production of grape wine.

The use of a clarifying agent composed of Bentonite, Activated Carbon, and Copper Sulfate to clarify and stabilize grape wine is considered as being consistent with good commercial practice. However, the Bentonite and Activated Carbon must be used within the limitations of 26 CFR 240.1057 and the addition of Copper Sulfate may not exceed 0.5 ppm with a residual level not in excess of 0.2 ppm.

Winemakers desiring to use this clarifying agent in the treatment 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.