Different cultures have different techniques of cooking food in clay pots. Some use pots that are fully finished by burnishing and therefore do not require the pot to be soaked each time before use. Some are unfinished and must be soaked in water for 30–45 minutes before each use to avoid cracking. The design and shape of the pot differ slightly from one culture to another to suit their style of cooking. Seasoning is important to prevent cracking of the vessel when exposed to high heat. Clay pots are initially seasoned with oil and hot water but may be fully seasoned only after the first several uses, during which food may take longer to cook. It is also essential to avoid sudden temperature changes, which may cause the pot to crack. Heat should be started low and increased gradually both on the stovetop and in the oven. The food inside the pot loses little to no moisture because it is surrounded by steam, creating a tender, flavorful dish. Water absorbed within the walls of the pot prevents burning so long as the pot is not allowed to dry completely. Because no oil needs to be added with this cooking technique, food cooked in clay is often lower in fat than food prepared by other methods.