Straight Whiskey is a US term for a Whiskey produced under the following guidelines:

• made up of at least 51% of a specific type of corn (corn, rye, wheat),
• the spirit was not distilled to more than 80% ABV and had 62,5% ABV or less when filled into the casks,
• the casks must be new and made exclusively up of American white oak and must be burned out before the filling,
• got bottled with at least 40% ABV.

The adding of caramel color is forbidden.

see also: Bourbon, Rye Whiskey