A mold form fryer utilizing a top conveyor that transports snack pieces through a constant velocity oil stream without the need of a bottom mating mold or conveyor. Herein, the form fryer having a fryer housing for controlling the frying atmosphere is provided with a top conveyor disposed above a fryer oil pan positioned longitudinally through the fryer. Uncooked snack pieces are provided to the fryer oil pan by a bottom entrance conveyor. A steam shield separates a front-end vestibule from the downstream portion of the fryer housing, and inert gas manifolds introduce inert gas into the front-end vestibule, thereby providing a sufficiently low oxygen and sufficiently low condensable gas or steam environment near the product submerging point.