A process and apparatus for quenching a metal workload from an elevated heat treating temperature are disclosed. The process includes the step of flowing a vegetable oil quenchant over the metal workload to provide a cooling rate sufficient to transform the metal substantially completely to a desired second phase comprising martensite, bainite, pearlite, or a combination thereof within a preselected time period. The apparatus includes a quenching chamber that has a base, an upper housing, a door, and an associated actuator for opening and closing the quenching chamber. The apparatus also includes a vessel for holding a volume of a vegetable oil quenchant, means for conducting the vegetable oil quenchant from the vessel to the quenching chamber, and means disposed in the quenching chamber for flowing the vegetable oil quenchant over a metal workload disposed in the quenching chamber.