The American Bourbon Whiskey must consist of at least 51% corn. In addition, rye or barley is used for the production. Further specifications regarding alcohol content are: 80% vol. must not be exceeded during production and 62.5% vol. at the beginning of the maturing process.
Bourbon Whisky must be stored for at least 2 years in flamed oak casks. Maturation periods of less than 4 years must also be specially indicated on the label. It is also prohibited to use colorants and the prescribed alcohol content in the bottle is 40-62.5% vol.
The designations are regulated by the authorities and divided into the following categories: