In a post-mix beverage dispenser system including beverage concentrate containers and a storage tank for the supply of diluent through an electromagnetically actuated valve, the beverage concentrate is provided to the mixing station in a series of individual pulsed portions by a reciprocating piston pump coupled to the containers for the beverage concentrate. An electromechanical control circuit is also provided for rhythmically opening and closing the electromagnetic valve for a pulsed supply of diluent in synchronism with the pulsed delivery of the beverage concentrate for providing a mixture of precise proportions.