Slipknot Limited Edition Anniversary Iowa Whiskey – Slipknot and Cedar Ridge have partnered to offer a limited edition whiskey in celebration of the 20th anniversary of the bands groundbreaking second album, IOWA. This selection of blended straight whiskies is 60 percent rye and 40 percent bourbon. The higher rye content gives Slipknot’s Iowa Anniversary whiskey a heavy spice influence that balances the rich flavor of Iowa corn.