Smooth Ambler Old Scout Single Barrel Select 12 Year is a bottle of powerful awesome. A single barrel cask strength expression, each bottling of Old Scout Single Barrel Select is unique in age and proof. The first thing you need to know is that it's a high-corn Bourbon. the mash bill includes 84% corn, 8% rye, and 8% malted barley. Most people think that this yields a sweeter, mellow Whiskey. But since it's bottles at cask strength, it's mellow at full volume.