(a) In general
The wine spirits authorized to be used in wine production shall be brandy or wine spirits produced in a distilled spirits plant (with or without the use of water to facilitate extraction and distillation) exclusively from—

(1) fresh or dried fruit, or their residues,

(2) the wine or wine residues, therefrom, or

(3) special natural wine under such conditions as the Secretary may by regulations prescribe;

except that where, in the production of natural wine or special natural wine, sugar has been used, the wine or the residuum thereof may not be used if the unfermented sugars therein have been refermented. Such wine spirits shall not be reduced with water from distillation proof, nor be distilled, unless regulations otherwise provide, at less than 140 degrees of proof (except that commercial brandy aged in wood for a period of not less than 2 years, and barreled at not less than 100 degrees of proof, shall be deemed wine spirits for the purpose of this subsection).

(b) Withdrawal of wine spirits

(1) The proprietor of any bonded wine cellar may withdraw and receive wine spirits without payment of tax from the bonded premises of any distilled spirits plant, or from any bonded wine cellar as provided in paragraph (2), for use in the production of natural wine, for addition to concentrated or unconcentrated juice for use in wine production, or for such other uses as may be authorized in this subchapter.

(2) Wine spirits so withdrawn, and not used in wine production or as otherwise authorized in this subchapter, may, as provided by regulations prescribed by the Secretary, be transferred to the bonded premises of any distilled spirits plant or bonded wine cellar, or may be taxpaid and removed as provided by law.

(3) On such use, transfer, or taxpayment, the Secretary shall credit the proprietor with the amount of wine spirits so used or transferred or taxpaid and, in addition, with such portion of wine spirits so withdrawn as may have been lost either in transit or on the bonded wine cellar premises, to the extent allowable under section 5008(a). Where the proprietor has used wine spirits in actual wine production but in violation of the requirements of this subchapter, the Secretary shall also extend such credit to the wine spirits so used if the proprietor satisfactorily shows that such wine spirits were not knowingly used in violation of law.

(4) Suitable samples of brandy or wine spirits may, under regulations prescribed by the Secretary, be withdrawn free of tax from the bonded premises of any distilled spirits plant, bonded wine cellar, or authorized experimental premises, for analysis or testing.

(c) Distillates containing aldehydes
When the Secretary deems such removal and use will not jeopardize the revenue nor unduly increase administrative supervision, distillates containing aldehydes may, under such regulations as the Secretary may prescribe, be removed without payment of tax from the bonded premises of a distilled spirits plant to an adjacent bonded wine cellar and used therein in fermentation of wine to be used as distilling material at the distilled spirits plant from which such unfinished distilled spirits were removed.