American rye whiskey: In the United States, rye whiskey is, by law, made from a mash of at least 51 percent rye. (The other ingredients in the mash are usually corn and malted barley.) It is distilled to no more than 160 U.S. proof (80% abv) and aged in charred, new oak barrels. The whiskey must be put in the barrels at no more than 125 proof (62.5% abv). Rye whiskey that has been aged for at least two years and has not been blended with other spirits may be further designated as straight, as in "straight rye whiskey".