Abstract: A system is provided for making frozen comestibles, and the like, having an over-run. The system comprises a swept surface heat exchanger which includes a manifolded cylinder in which is disposed a tube having a dasher. Refrigeration means are connected to the manifolded cylinder and the tube is provided with an inlet and an outlet. The system further comprises an air/mix or over-run control system which includes a positive displacement pump having a variable drive, an inlet for a mix, and an outlet. A magnetic flow meter receives mix from the pump outlet and provides a signal proportional to the flow of mix therethrough. An air mass flow control is connected between the mix conduit and a source of pressured air. A control circuit, such as a programmable computer, receives signals from the flow meter and controls both the variable drive on the pump and the pressured air through the air mass flow control.