01At Least 51% Corn
The mash must contain at least 51% corn. The rest can include rye, wheat, and malted barley.
The Short Version
Bourbon Is
American Whiskey
With Rules.
Bourbon starts with grain, yeast, water, distillation, and oak just like other whiskey. What makes it bourbon is a specific set of federal standards for grain, proof, barrels, and where it's made.
And no, bourbon does not have to come from Kentucky. It does have to be distilled and aged in the United States.
The Six Rules
What Makes It Bourbon
Six requirements. No mystery. Just whiskey with a rulebook.
01
02Made in the United States
Bourbon must be distilled and aged in the United States. Kentucky is famous for it, but it isn't required.
03160 Proof or Less Off the Still
It can come off the still at no more than 160 proof, or 80% alcohol by volume.
04New Charred Oak
The spirit must be stored in new charred oak containers.
05125 Proof or Less Into the Barrel
When it enters the barrel, bourbon must be 125 proof or lower.
06No Flavoring or Coloring
No coloring, flavoring, or blending materials are permitted in bourbon whiskey.
One More Label
What Does “Straight Bourbon” Mean?
“Straight” adds an aging requirement. Straight bourbon follows the same bourbon rules and must spend at least two years in new charred oak.
If a whiskey is less than four years old, federal labeling rules generally require an age statement.
Quick Myth Check
Does Bourbon Have to Come From Kentucky?
Nope.
Kentucky has an enormous bourbon tradition. But the federal standard says United States, not Kentucky.
Worth Remembering
Bourbon Is Whiskey.
Not All Whiskey Is Bourbon.
Whiskey is the bigger family. Bourbon is one specific American style with rules for grain, proof, origin, and oak. Know the rules, then enjoy the pour.
Official Sources
Want the Legal Language?
The standards above are based on current federal regulations and TTB guidance.