Rev. Rul. 64-266

Defoaming agents, composed of polyoxyethylene-40-monostearate and silicon dioxide which meet the requirements of the Food and Drug Administration, Department of Health, Education, and Welfare, may be used in the production of wine, within the general limitations of section 240.524 of the Wine Regulations. Such defoaming agents which are 100 percent active may be used in amounts not exceeding 0.15 of a pound per 1,000 gallons of wine while such a defoaming agent which is 30 percent active may be used in amounts not exceeding 0.5 of a pound per 1,000 gallons of wine. In either case, the silicon dioxide must be completely removed by filtration.

Winemakers desiring to use these products as defoaming agents in the production of wine may obtain approval of the Assistant Regional Commissioner, Alcohol and Tobacco Tax, by filing notice pursuant to the provisions of section 240.1052 of the regulations.