Creaming is a technique in cooking to describe the blending of dry ingredients (usually sugar) with a solid ingredient such as shortening or butter. This technique is often used when making cookies or cakes. Once the dry ingredients are mixed with the solid and air is incorporated the mixture becomes light and fluffy. The small air bubbles that are formed during this technique lock in the solids and serve as a leavening agent once the product is baked. Butter is traditionally used as the major creaming ingredient but shortening is often a better leavening agent because shortening works best at high temperatures, better than butter does. Butter has a low melting point. Butter does however; allow bigger air bubbles because of the crystalline structure of the fat in butter. Shortening has more nitrogen bubbles in it and bubble emulsifiers and both act as great leavening agents.