bourbon must be made from at least 51% corn. Most bourbons are distilled in Kentucky, and aged in charred white oak barrels for at least two years. Depending on the manufacturer and process, wheat, rye or barley may be used in production.
Bourbon is an American whiskey made from corn and other grains, and is strongly associated with the state of Kentucky. Bourbon can, however, be legally produced anywhere in the United States. An Act of Congress passed in 1964 made bourbon the official spirit of the United States.