The invention relates to a method of presterilizing an aseptic tank (1) and connectingconduits (8, 10, 11, 13, 14, 16). A certain amount of cold water is pumped into thetank (1) and the conduits (8, 10, 11, 13, 14, 16) and is caused to pass through a heatexchanger (6). In the heat exchanger, the water is heated to 120-150 C, whereafterthe water is pumped across the tank (1) and conduits (8, 10, 11, 13, 14, 16) during10-20 minutes.
