Abstract: A method and apparatus for mixing fluids, such as beverage syrup and water, uses countercurrent injection to improve blending of the fluids. A mixing chamber has a first inlet through which a first fluid is fed to the mixing chamber, and a second inlet through which a countercurrent injection nozzle extends and is operative to inject a second fluid into a stream of the first fluid. The countercurrent injection nozzle is equipped with a check valve to control the flow of fluid into the mixing chamber. The mixing chamber may include additional inlets that may be fitted with countercurrent injection nozzles to permit the countercurrent injection of other fluid, such as flavorings, into the stream of the first fluid.