A method and apparatus provides for dispensing a liquid concentrate. The source pressure of a liquid diluent is changed by a boost pump (52) to bring the pressure of the diluent to an elevated pressure. The diluent then enters an aspirator assembly (10) wherein the concentrate and diluent are mixed to form a use solution. The dynamic pressure of the diluent entering the aspirator assembly (10) is sufficient so that the amount of concentrate delivered over time is more constant.