A method and apparatus is disclosed for separating a slurry into liquids and solids in a pressure filter apparatus and for forming a substantially dry and often loosely packet filter solids cake wherein a high temperature and high pressure steam is introduced into an initially formed filter cake in the pressurized filter apparatus to force the steam into the interstices of the formed filter cake and then pressure within the filter apparatus is reduced to permit the steam to flash and to expand within the interstices to absorb any remaining fluids within the formed filter cake and to cause the filter cake to become substantially dry and loosely packed. The filtered solids cake is then discharged from the filter apparatus.