Pizza is available frozen. Food technologists have developed ways to overcome challenges such as preventing the sauce from combining with the dough and producing a crust that can be frozen and reheated without becoming rigid. Modified corn starch is commonly used as a moisture barrier between the sauce and crust. Traditionally the dough is pre-baked and other ingredients are also sometimes precooked. There are frozen pizzas with raw ingredients and self-rising crusts. A form of uncooked pizza is available from take and bake pizzerias. This pizza is created fresh using raw ingredients, then sold to customers to bake in their own ovens and microwaves.