Abstract: An apparatus for more effectively controlling the precooking operation by separating the precooking procedure into multiple distinct zones and controlling the temperature in each cooking zone. A porous conveyor belt conveys shrimp from a feeder tank at a temperature of approximately 40.degree. F. into zone 1 maintained at a temperature of 212.degree. F. and subsequently into zone 2 in which the temperature is maintained at 212.degree. F. and finally into zone 3 and optionally into zone 4 maintained at a temperature less than 212.degree. F. In zone 1 the mixture of air and steam from both above and below the shrimp will condense on the surface of the shrimp for control cooking in zone 1 in which the shrimp is heated to approximately 116.degree. F. In zone 2, the same cooking procedure raises the cooking temperature of the shrimp to approximately 173.degree. F. In zone 3, and optionally in zone 4, a controlled cooking atmosphere is maintained at 180.degree. F. to 212.degree. F.