The invention relates to a pasteurization plant and a method of operating a pasteurization plant. During operation of the pasteurization plant, a tempered process liquid is applied to containers filled with food products in one or more treatment zone(s). At least a part of the process liquid is fed back to the treatment zone(s) for reuse in at least one recirculation loop. At least a partial quantity of a volumetric flow of the process liquid fed per unit of time via the at least one recirculation loop is diverted to create at least one partial flow, circulated through at least one cleaning device and then returned to a recirculation loop or a treatment zone again. The at least one cleaning device comprises a membrane filtration device and an ion exchange device.
