Abstract: An improvement for a stretch blow molding apparatus, including a cryogenic liquid pulse pump disposed in sealed fluid connection between a cryogenic liquid reservoir and a stretch blow molding machine, a subcooler connected between the reservoir and the pulse pump for supplying cryogenic liquid at a preselected temperature, a vacuum jacket casing disposed generally surrounding a stretch blow rod, the reservoir, and the pulse pump for preventing vaporization of cryogenic liquid prior to delivery into a container, and control means for controlling the pulse pump to deliver a preselected amount of cryogenic liquid into the container through the stretch rod during a predetermined time interval beginning at a preselected time after formation of the container.