A system for mixing beverage components in a predetermined ratio is characterized by a housing having a mixing chamber therein, first and second inlets to the chamber and an outlet from the chamber. A first beverage component is flowed through the first inlet to the mixing chamber and a second beverage component is flowed through the second inlet to the chamber for mixing of the components in the chamber and exit of the mixture from the chamber through the chamber outlet. The pressure of the second beverage component in the second inlet is sensed upstream from the chamber and the flow of at least one of the first and second beverage components to the chamber is controlled in accordance with the sensed pressure to deliver to the mixing chamber a predetermined ratio of the first and second beverage components.