5 rules that make it bourbon

All bourbon is whiskey but not all whiskey is bourbon. But what actually distinguishes bourbon from all the rest?

According to Maker's Mark COO Rob Samuels, it comes down to these five things. He should know, his family has been making bourbon for generations and they started one of the world's most recognizable brands. His grandmother is the one who came up with Maker's Mark's signature hand-dipped red wax top. He currently runs the operations and knows how important it is to follow the rules.

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1. It must be made in the United States. Contrary to popular belief, it doesn't have to be made in Kentucky, although 95 percent of the world's supply is.

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2. Aging must take place in a new, charred, oak barrel. Maker's Mark gets its from ISC (Independent Stave Company) in Kentucky. Whiskey can be aged in used barrels and often is. The bourbon must be aged for at least two years to be considered a straight bourbon.

3. The mash must be at least 51 percent corn. Maker's Mark is way above the minimum at 70 percent.

4. The whiskey cannot enter the barrel at higher than 125 proof. It cannot enter the bottle at a proof less than 80.

5. Nothing can be added but water and only to lessen the proof when necessary. Other whiskeys can add color and flavor. Not bourbon, it must be au naturel.

CORRECTION: Rob Samuels is the COO of Maker's Mark, and whiskey cannot enter the barrel at higher than 125 proof.