Oats are wonderful in a porter or stout. Oatmeal lends a smooth, silky mouthfeel and a creaminess to a stout that must be tasted to be understood. Oats are available whole, steel-cut (i.e. grits), rolled, and flaked. Rolled and flaked oats have had their starches gelatinized (made soluble) by heat and pressure, and are most readily available as "Instant Oatmeal" in the grocery store. Whole oats and "Old Fashioned Rolled Oats" have not had the degree of gelatinization that Instant have had and must be cooked before adding to the mash. "Quick" oatmeal has had a degree of gelatinization but does benefit from being cooked before adding to the mash. Cook according to the directions on the box (but add more water) to ensure that the starches will be fully utilized. Use 0.5-1.5 lb. per 5 gal batch. Oats need to be mashed with barley malt (and its enzymes) for conversion.