The mixing of ingredients is an important step in cooking. The techniques used in combining ingredients greatly influences the quality of the final product. Nowhere in cooking is this more evident than in baking but it is equally important in such procedures as sauce making where emulsification, the incorporation of hot liquid and starch, the mounting of a sauce with butter, etc. are special skills which must be mastered by every cook. In baking such procedures as the folding of egg whites or whipped cream into cake batter, mousses and moulds is another special skill. The mixing of batters in general is a science in itself and so on.