See British Origin American-Style Imperial Porter Imperial porters are very dark brown to black in color. No roast barley or strong burnt/astringent black malt character should be perceived. Medium malt, caramel and cocoa-like sweetness should be in harmony with medium-low to medium hop bitterness. This is a full bodied beer. Ale-like fruity esters should be evident but not overpowering and compliment malt derived sweetness and hop character. Hop flavor and aroma may vary from being low to medium-high. Diacetyl (butterscotch) levels should be absent.