The appropriate TTB officer has responsibility for determining whether products are fit or unfit for beverage purposes within the meaning of 26 U.S.C. 5111. This determination may be based either on the content and description of the ingredients as shown on TTB Form 5154.1, or on organoleptic examination. In such examination, samples of products may be diluted with water to an alcoholic concentration of 15% and tasted. Sale or use for beverage purposes is indicative of fitness for beverage use.