Grain whisky is the base of blended whisky. It is distilled in a continuous still from grains other than malted barley. It is cheaper to produce and has a very high yield, thus it is the staple of the industry. It does not, however, offer the same complexity and character as malt whisky, thus it is used as a cheaper base for a blend, with malt whisky included to bring depth and character. Recently, we've seen whisky makers defying the idea that grain whisky is not a stand alone product, and aside from single grain whiskies, we've also had the release of blended grain whiskies. Compass Box Hedonism is a sterling example, and is unlike anything you'll try.