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
Alcoholic drink benefits and risks of consuming alcohol in moderation." Alcoholic drinks are classified by the International Agency for Research on Cancer (IARC) as a Group 1 carcinogen (carcinogenic to humans). IARC classifies alcoholic drink consumption as a cause of female breast, colorectum, larynx, liver, esophagus, oral cavity, and pharynx cancers; and as a probable cause of pancreatic cancer. In the alcoholic drinks industry, congeners are substances produced during fermentation. These substances include small amounts of chemicals such as occasionally desired other alcohols, like propanol and 3-methyl-1-butanol, but also compounds that are never desired such as acetone, acetaldehyde and glycols. Congeners are