Specially denatured spirits may, under this part, be withdrawn from the bonded premises of a distilled spirits plant, free of tax, for:
All such withdrawals shall be made under a consent of surety on the proprietor's operations or unit bond, as prescribed in § 28.58(c).
27 C.F.R. § 28.151
48 Stat. 999, as amended, 72 Stat. 1362; 19 U.S.C. 81c , 26 U.S.C. 5214