A system for controlling the progress of the manufacture of at least one product by vertical semi-continuous direct chill casting, in particular from aluminium alloy, in a fixed mold, the control system includes a dummy bottom configured to form a movable lower bottom of the fixed mold and to carry the product during casting; a weighing cell, on which the dummy bottom is arranged to rest, the weighing cell being configured to take measurements representative of the mass of the product carried by the dummy bottom during casting; and a support of the dummy bottom, to which the weighing cell is linked, configured to lower the false bottom relative to the fixed mold, substantially in a vertical direction, during casting; and a processing unit connected to each weighing cell, and configured to process the measurements, and calculate the variation in the mass of the product over time.