The proprietor must gauge spirits, wine, and alcoholic flavoring materials when required to do so by the appropriate TTB officer or when the spirits, wine, or flavoring materials are:
(a)
Produced and entered for deposit;
(b)
Filled into packages from storage tanks;
(c)
Transferred or received in bond;
(d)
Transferred between operational accounts;
(e)
Mixed in the manufacture of a distilled spirits product;
(g)
Reduced in proof before bottling;
(h)
Voluntarily destroyed;
(i)
Removed or withdrawn from bond;
Code of Federal Regulations
(
26 U.S.C. 5204, 5559
)