Popovers are made with a batter similar to a pancake batter, containing eggs, milk, butter, and flour. As the batter is beaten continuously, air is captured within the thin batter. Then, as the popover bakes, the heat cooks and releases the excess liquid continued in the batter as steam so it "puffs" up, thus leavening the batter and forming puffed bread. Outside, the batter bakes into a golden brown, crispy thin crust while inside the batter forms a light and airy textured crumb that is also very thin. Popovers are made with a plain batter or with a batter that has been combined with cheese, herb, seasonings, and other ingredients to enhance the flavor. When served, the popover may be accompanied with condiments such as flavored or plain butters, jams, jellies, and preserves.