Abstract: The invention provides a method for sterilizing liquids by brief heating, comprising exposing a pressurized stream of already sterilized liquid to a pressure reduction, an evaporable partial quantity of the liquid being induced to assume vapor form while the remaining part of the liquid quantity is cooled, introducing vapor thus formed into a compressor in which said vapor is compressed and is heated due to said compression and is mixed with and condensed in a stream of pressurized liquid which is supplied to the compressor and, by being mixed with ward condensate, is raised to a temperature which is equal to or exceeds that required for sterilization, and maintaining the sterilization temperature of the said heated and pressurized stream of liquid for the length of time required for sterilization, whereupon the liquid is subjected to the initially-mentioned pressure reduction during which an evaporable part quantity of the liquid is evaporated and is again subjected to the treatment cycle while the remaining