Reactor for conducting sterile fermentation processes of a product in the solid state.

reactor for conducting sterile fermentation processes of a product in solid form, comprising a tank (1) jacketed (3) with a door (10) at its lower part, a cover (11 ) in its upper part, a grid (15) to the bottom of the tank (1), a stirrer (17) mobile in rotation around two vertical axes (XX; YY) under the control of a drive member (M) and a planetary drive system (29), a circuit for circulating a gas through the vessel (1) between an inlet conduit (C3) and an outlet duct (C15), and systems control and regulation of the temperature and humidity of the product being cultured. Such a reactor makes it possible to conduct fermentation processes in the solid state under perfectly sterile conditions.