Alcoholic drink which contains a very high level of alcohol and "does not contain any added flavoring" is commonly called a neutral spirit. Generally, any distilled alcoholic beverage of 170 US proof or higher is considered to be a neutral spirit. Most yeasts cannot reproduce when the concentration of alcohol is higher than about 18%, so that is the practical limit for the strength of fermented drinks such as wine, beer, and sake. However, some strains of yeast have been developed that can reproduce in solutions of up to 25% ABV. Shot sizes vary significantly from country to country. In the United
Caffeinated alcoholic drink inferred that caffeinated alcoholic drinks cause one to act in ways that would be less likely if one were drinking non-caffeinated alcoholic drinks. The adverse effects of caffeinated alcoholic drinks have led to increased regulation. Under the Federal Food, Drug, and Cosmetic Act, a substance intentionally added to food (such as caffeine in alcoholic drinks) is deemed "unsafe" and is unlawful unless its particular use has been approved by FDA (Food and Drug Administration) regulation. The substance is subject to a prior sanction until the substance is Generally Regarded As Safe (GRAS). In order for a substance to be characterized