A method for producing a container from a blank, inside a forming unit having a mold and a movable insert controlled by a variable-flow solenoid valve, a control unit linked to the solenoid valve. The method comprises developing a boxing curve characterizing the successive positions of the insert; determining, based on a reference blowing curve, points of inflection; measuring, on the boxing curve, distances actually travelled by the insert between points in time, some of which correspond to these points of inflection; and comparing the values of the measured distances with nominal values. If there is a difference between a measured value and a nominal value, controlling, by the control unit, a modification in the flow rate setpoint of the solenoid valve for the next production cycle.