27 CFR 19.307: Distillates containing extraneous substances.

(a) Use in production. Distillates that contain substantial quantities of fusel oil, aldehydes, or other extraneous substances may be removed from the distilling system before the production gauge and promptly added to fermenting or distilling material at the distillery where produced.

(b) Use at adjacent bonded wine cellar. Distillates that contain aldehydes may be removed, without payment of tax, to an adjacent bonded wine cellar for use in fermentation of wine to be used as distilling material at the distilled spirits plant from which the distillates were removed. The removal of distillates to an adjacent bonded wine cellar must be done as provided in § 19.419. The receipt and use of those distillates must conform to the requirements of part 24 of this chapter.