The last method is called the continuous process and is usually used in commercial bakeries because it creates a consistent product in large volumes. Ingredients are fed into the continuous mixer in either one or two stages. A one-stage process mixes all of the ingredients together and feeds them into an emulsion head. Upon entry into the emulsion head, air is incorporated, fully mixing the batter. In a two-stage process, the ingredients are blended separately in different tanks according to the recipe. The speed of the mixer is controlled, as well as air flow to help mix the batter. The final batter may then go through a static mixer (a pipe with a spiral blade inside) to be deposited in a tube pan, depositor, or hopper.