Essences or extracts (preparations of natural constituents extracted from fruit, herbs, berries, etc.) may be used in the production of any formula wine except agricultural wine. The essences may be produced on wine premises or elsewhere. Where an essence contains spirits, use of the essence may not increase the volume of the wine more than 10 percent nor its alcohol content more than four percent by volume.

(Sec. 201, Pub. L. 85-859, 72 Stat. 1386, as amended (26 U.S.C. 5386))