DEEP FRYERS: A deep fryer has only one use – to cook foods in hot fat. Yet because of the popularity of fried foods, this function is an important one. Automatic deep fryers are powered by either gas or electricity and have thermostatic controls that maintain fat at preset temperatures. Automatic fryers remove food from the fat automatically after a present time. Pressure fryers are covered fry-kettles that fry foods under pressure. Foods cook faster, even at a lower temperature.