Abstract: A valve for controlling the flow of air and liquid product mix from a liquid product reservoir to a freezing chamber in a soft ice cream dispensing machine has a lower tubular member snugly yet removably received within a tubular communicating line between the reservoir and freezing chamber. An air retaining chamber is fixed to the upper portion of the lower tubular member and communicates therewith. An upper tubular member fixed to the chamber extends upward to a point above the maximum anticipated level of the liquid product in the reservoir. The lower end of the upper tubular member extends somewhat inside the chamber. The upper tubular member has a small aperture near the lower end thereof opening into the liquid product reservoir. A checkvalve is attached to the lower end of the upper tubular member for retaining air in the air retaining and freezing chambers to assure the desired overrun in the ice cream.