Robust porters are black in color and have a roast malt flavor, often reminiscent of cocoa, but no roast barley flavor. These porters have a sharp bitterness of black malt without a highly burnt/charcoal flavor. Caramel and other malt sweetness should be present and in harmony with other distinguishing porter characters. Robust porters range from medium to full in body and have a malty sweetness. Hop bitterness is medium to high, with hop aroma and flavor ranging from negligible to medium. Diacetyl is acceptable at very low levels. Fruity esters should be evident, balanced with roast malt and hop bitterness.