Abstract: A vessel for treating meat with a vacuum and carbon monoxide or purified smoke comprises a cylindrical wall, a closed axial end and an open axial end, a door for closing the open axial end, a rack with plural shelf supports for supporting trays of means to be treated, horizontal guide rails fixed to opposite sides of the vessel interior enabling the rack to be slid through the door and onto the guide rails while loaded with meat to be processed, a port for connecting the interior of the vessel to a vacuum pump, and a second port for connecting the interior of the vessel to a source of carbon monoxide or purified smoke.