Old Elk Four Grain Straight Bourbon Whiskey is made up of a blend of four cereal grains — corn, wheat, barley and rye. Coming in at 105.9 proof, the distillery boasts flavors of almond, vanilla, maple and spices. Four Grain was aged 6-7 years with a mask bill containing 51% corn, 22.5% wheat, 19% barley, and 7.5% rye.