27 CFR § 25.41
Measuring system required
April 24, 2020
The brewer shall accurately and reliably measure the quantity of beer transferred from the brewery cellars for bottling and for racking. The brewer may use a measuring device, such as a meter or gauge glass, or any other suitable method.
(Sec. 201, Pub. L. 85-859, 72 Stat. 1395, as amended (26 U.S.C. 5552))