Abstract: A pressure cooker canning unit for batch canning, the canning unit including a pressurizable retort having a highly accurate control and monitoring system for temperature regulation and recordation, the retort having a pressure gauge and a thermometer tree for visual monitoring of the pressure and temperature in the retort, a temperature probe and connected temperature recording device for continuous recording of the temperature within the retort and a pressure relief valve for safely releasing excess pressure in the retort, the retort being heated by a gas burner with a gas flow regulated by a unique flow control valve modulated by the pressure within the retort for maintaining a constant temperature within the retort.