A plant for heat treating fluid foodstuffs, such as milk, milk based products, baby food, baby food liquid concentrates, or nutritious drinks. The plant comprises a´heat treatment apparatus (1) having a fluid foodstuff inlet arranged at a top of the heat treatment apparatus (1), a fluid foodstuff outlet arranged at a bottom of the heat treatment apparatus (1), and a first steam inlet arranged at a top of the heat treatment apparatus (1). The fluid foodstuff is subjected to heat treatment by feeding live steam and/or flash steam into the heat treatment apparatus (1). The live steam is fed into the heat treatment apparatus (1) by means of a live steam conduit (3) connected to the first steam inlet. The plant further comprises a flash vessel (10) having a fluid foodstuff inlet at a top of the flash vessel (10) and a fluid foodstuff outlet at a bottom of the flash vessel (10). The fluid foodstuff outlet of the heat treatment apparatus (1) is connected to the fluid foodstuff inlet of the flash vessel (10) by means of aconduit (9) and a pump (6). The fluid foodstuff outlet of the flash vessel (10) is connected to a conduit (12) and a pump (13) for draining off fluid foodstuff from the flash vessel (10). The flash vessel (10) further comprises a flash steam outlet arranged at the top of the flash vessel (10), the flash steam outlet being connected to a first flash steam conduit (8). The first flash steam conduit (8) is connected to an inlet of a compression arrangement (16). The first flash steam conduit (8) is adapted for feeding the flash steam to the compression arrangement (16), in which compression arrangement (16) the flash steam is compressed, and a second flash steam conduit (14) is connected to an outlet of the compression arrangement (16), the second flash steam conduit (14) is adapted for transferring the flash steam to the heat treatment apparatus (1).
