A method for controlling a molding unit (10) for the forming of a container made of thermoplastic material by blow molding of a preform, with the unit (10) including: a carriage (24) that carries, in a stationary manner, a mold bottom (16); at least one stationary cylinder (32) housing a piston (98) that slides between a lower rest position and an upper boxing position in which it pushes the carriage (24) from an intermediate position to an upper molding position; actuating elements for moving the carriage (24) from its upper molding position to a lower extraction position; with the method including an extraction step (E4) wherein the movement of the carriage (24) toward its lower extraction position is initiated while the piston (98) has not yet returned into its lower rest position.