The appropriate TTB officer may, at any time, require you to submit samples of:

(a) Cereal beverage, saké, or any fermented product produced at the brewery,

(b) Materials used in the production of cereal beverage, saké, or any fermented product; and

(c) Cereal beverage, saké, or any fermented product, in conjunction with the filing of a formula.

(26 U.S.C. § 5415, 5555, 7805(a))