27 C.F.R. § 19.256 – Tax on wine.

(a) Imposition of tax. All wine (including imitation, substandard, or artificial wine, and compounds sold as wine) produced in or imported into or brought into the United States is subject to tax pursuant to 26 U.S.C. 5041 or 7652. The proprietor may be liable for wine taxes under 26 U.S.C. 5362(b)(3) for wine that is transferred in bond to the proprietor's distilled spirits plant. The proprietor may not remove wine from the bonded premises of a distilled spirits plant for consumption or sale as wine. (See 26 U.S.C. 5362.)
(b) Liability for tax. Except as otherwise provided by law, the proprietor is liable for the tax on wine transferred in bond to the proprietor's distilled spirits plant from a bonded wine cellar or from another distilled spirits plant until the proprietor uses the wine in the manufacture of a distilled spirits product or properly disposes of the wine as provided elsewhere in this part.
(26 U.S.C. 5041, 5362, 7652)