Since 1964 Bourbon is an officially registered title exclusively for American Whiskey.
For having this title he shall have to fulfil:
• Only whiskey produced in the United States can be called bourbon
• Bourbon must be made from a grain mixture that is at least 51% corn.
• Bourbon must be distilled to no more than 160 (U.S.) proof (80% alc. volume).
• Bourbon, must be bottled at not less than 80 proof (40% alc. by volume.)
• Bourbon must be entered into the barrel for aging at no more than 125 proof (62.5% alc. by volume).
• Bourbon must be aged in new, charred oak barrels.
• Bourbon has no minimum specified duration for its aging period.
However to called Straight Bourbon:
• has been aged for a minimum of two years, and has no added coloring, flavoring,
or other spirits may be called Straight bourbon.
• Bourbon that is labeled as Straight that has been aged for a period less than four years
must be labeled with the duration of its aging.
• Bourbon that has an age stated on its label must be labeled with the age of the youngest
whiskey in the bottle (not counting the age of any added neutral grain spirits in a Bourbon
that is labeled as Blended, as neutral grain spirits are not considered whiskey under the
regulations and are not required to be aged at all).
• Bourbon that is labeled as Blended (or as ‘a blend’) may contain added coloring, flavoring,
and other spirits; however, at least 51% of such a product must be Straight Bourbon.
The most known Bourbons comes from Kentucky: Jim Bean, Wild Turkey, Buffalo Trace, Maker’s Mark etc.
Also Jack Daniel’s Tennessee Whiskey is actually a Bourbon but he don’t append it in his Name.