Abstract: A food heating method and apparatus are disclosed in which a heating time length suitable to the food to be cooked is determined by automatically detecting a change in humidity or concentration of the vapor or gas respectively liberated from the food. The initial temperature of the food is measured, and an additional heating time length is calculated from the measured initial temperature and the heating time length required before the detection of the humidity or gas concentration as the case may be, thus determining a total heating time length for properly cooking up the food.

Abstract: Apparatus for controlling heating time for food placed in a cooking apparatus such as a microwave oven in which heating time required for the humidity of the food which varies with the heating of the food to reach a representative humidity value after abrupt change with a positive gradient is measured, and the product of the measured heating time multiplied by a predetermined heating time coefficient which is inherent in the particular food is added to the measured heating time so that the sum represents the total required heating time for the food.