An apparatus (10) for the pressurized recirculation of organic material comprising a reactor vessel (12) capable of being pressurized and in which both anaerobic digestion and aerobic composting of organic material may occur, the reactor vessel (12) having both an inlet (14) and an outlet (16) for organic material, together with a conveyor means (18, 20, 22, 28, 29, 30, 32, 34 and 36) to convey organic material to the inlet (14) and from the outlet (16), whereby organic material may be transferred between the outlet (16) and the inlet (14) to achieve recirculation and rearrangement thereof while maintaining a pressurized state. A method for the pressurized recirculation of organic material is also described.