In the electrolytic reduction of alumina an excess amount of cryolite bath is utilized to increase the amount of metal plated out. The carbon anodes are lowered into the excess bath to raise the liquid level of the bath above the normal operating level. Alumina is then added to saturate the upper portions of the excess bath and to form a thick crust over the pot. The carbon anodes are raised to their normal operating position and the bath periodically charged with alumina over the remainder of the run without breaking the crust. Molten aluminum leaches from the crust and augments the metal plated out and deposited at the bottom of the bath.