A method and an apparatus for producing and providing sterile water comprising an inlet for process water; a recuperator for preheating process water and for cooling down the sterile water; a heating circuit comprising a pump, a heater for heating preheated process water and a heat retention section for keeping heated process water hot; a temperature sensor for measuring a current temperature of the sterile water leaving the heat retention section; a flow control valve located downstream of the temperature sensor; and a bypass between the flow control valve and the heater. The flow control valve keeps a volume flow in the heating circuit constant, the recuperator cools down the sterile water of a first partial volume flow, when such a first partial volume flow of sterile water is taken from the heating circuit, the bypass returns into the heating circuit a second partial volume flow of sterile water.