The invention concerns a method for producing a food or biotechnological product including one or more steps, said one or more steps being implemented in a medium, said one or more steps implemented in a medium being a fermentation step, which consists in: during at least one of the steps of the method in controlling the redox potential of the medium of the step concerned. Said method is characterized in that it consists in carrying out the process as follows: regulating at a predetermined setpoint level the redox potential of the medium of the step whereof the redox potential is controlled by controlled additions of a process gas into the medium concerned and proceeding to the step following the step concerned in the process when said setpoint value is reached so as to carry out at least one of said steps of the process in reducing condition and at least one of said steps of the process in oxidizing condition.
