(a) General. Proprietors of a bonded wine premises and a taxpaid wine bottling house premises shall be held strictly responsible for the correct determination of the quantity and alcohol content of wine removed as well as for the correct determination of carbon dioxide in artificially carbonated hard cider and in sparkling hard cider. As required by § 24.170, appropriate and accurate measures and instruments for measuring and testing the wine will be provided at each wine premises.

(b) Bottle or other container fill. Proprietors of bonded wine premises and taxpaid wine bottling house premises shall fill bottles or other containers as nearly as possible to conform to the amount shown on the label or blown in the bottle or marked on any container other than a bottle; but in no event may the amount of wine contained in any individual bottle, due to lack of uniformity of the bottles, vary from the amount stated more than 1.0 percent for 15.0 liters and above, 1.5 percent for 1.0 liter to 14.9 liters, 2.0 percent for 750 mL, 3.0 percent for 375 mL, 4.5 percent for 187 mL and 100 mL, and 9.0 percent for 50 mL; and in such case, there will be substantially as many bottles overfilled as there are bottles underfilled for each lot of wine bottled. Short-filled bottles or other containers of wine which are sold or otherwise disposed of by the proprietor to employees for personal consumption need not be labeled, but, if labeled, need not show an accurate statement of net contents.

(c) Tax tolerance. The net contents of bottles or other containers of untaxpaid wine in the same tax class filled during six consecutive tax return periods, as determined from the bonded wine premises proprietor's fill test records, shall not vary by more than 0.5 percent from the net contents as stated on the bottles or other containers. The bonded wine premises proprietor is liable for the tax on the entire amount of wine in the same tax class when that wine is removed from bond, without benefit of tolerance, when the fill of bottles or other containers exceeds a 0.5 percent average of a period which consists of six consecutive tax returns, or when filling is not conducted in compliance with good commercial practice.

(d) Fill tests. The proprietor shall test at representative intervals wine bottled or packed during the bottling or packing operation of each bottling or packing line to determine if the wine contained in the bottle or other container is in agreement with that stated on the label, bottle, or other container.

(e) Alcohol tests. The proprietor shall test the alcohol content by volume to determine the tax class of the wine and to ensure the alcohol content to be stated on the label is in agreement with the requirement of § 24.257.