Abstract: Apparatus for mixing two fluids has separate supply lines for delivering the fluids to a mixing head. Flow rate of fluid in one supply line is monitored by arranging a pressure transducer to measure a pressure drop across an orifice in an orifice plate arranged in the supply line and a controller is responsive to the detected flow rate to control flow rate of fluid in the other supply line to achieve a desired flow ratio of both fluids at the mixing head for producing a mixed fluid having the correct proportions of both fluids. The fluids may be a concentrate syrup and a plain or carbonated water to produce a beverage.