27 CFR § 19.248 - Standard effective tax rate.
(a) Establishing a standard effective tax rate for a product. The proprietor may establish a permanent standard effective tax rate for any eligible distilled spirits product, rather than calculate a separate effective tax rate for each batch of product made. If the proprietor elects to use this option, the proprietor must determine the permanent standard effective tax rate based on the least quantity and the lowest alcohol content of eligible wine or eligible flavors used to manufacture the product. Thus, the permanent standard effective tax rate is the highest tax rate that would apply to the product because it is based on a batch with the least amount of alcohol from eligible wine and flavors that qualify for the credit under 26 U.S.C. 5010. By using this method the proprietor forgoes the possible use of a lower tax rate in exchange for the convenience of using a permanent standard effective tax rate that does not have to be recomputed for each batch of product made. The proprietor must keep a permanent record of the standard effective tax rates established for each product, in accordance with § 19.615.
(b) Batches subject to a higher tax rate. Whenever the proprietor manufactures a batch of the product with a lesser quantity or lower alcohol content of eligible wine or eligible flavor, this will result in a higher tax rate on the product since the product will have less alcohol qualifying for the credit under 26 U.S.C. 5010 and a higher percentage of alcohol taxable at the rate published in 26 U.S.C. 5001. In such instances, the proprietor must keep the cased goods segregated from other completed cases of the same product subject to the permanent standard effective tax rate for that product. The proprietor must determine the tax rate for the nonstandard batch in accordance with § 19.247.
(c) TTB review of standard tax rates. If the appropriate TTB officer finds that the use of this procedure jeopardizes the revenue, or causes administrative difficulty, the proprietor upon notification from TTB must discontinue use of this procedure.