A popper 10 comprises a kettle 11 which includes a popping chamber 12, a burner 15 and a heat exchanger 16 to transfer the heat from the burner 15 to the popping chamber 12. There is a separation between the burner 15 and the popping chamber 12. The burner 15 may be a gas burner which produces exhaust gas which enters the hot gas chamber of the heat exchanger to heat the popping chamber 12. There may be stirrer 20 and a motor 19, or other type of agitator, to agitate the expandable food. A method of popping an expandable food is disclosed comprising the steps of firing the burner of the popper, allowing the popping chamber to get hot, introducing the expandable food to the popping chamber, heating until the food has popped, then removing the expanded food from the chamber and refilling with unexpanded food. Also disclosed is the apparatus not necessarily for expandable food, but instead with a heating chamber for heating a foodstuff.
