Abstract: Apparatus for heat treating a particulate commodity comprising an enclosure having a lower wall in the form of a concave, perforate deck, supply means for supplying pressurized fluid at a controlled temperature through the deck to fluidize and heat treat a bed of particles in the enclosure and transfer means for controlledly moving the particles continuously or stepwise along the deck. A method of heat treating the particulate commodity comprising supporting said commodity in a fluidized bed above a concave, perforate deck, supplying pressurized fluid at a controlled temperature through the deck to fluidize and heat treat the commodity, controlling the residence time of the commodity in the enclosure by controlledly moving the commodity along the deck using transfer means, and enhancing fluidization of the bed by reducing segregation within the bed using said transfer means. The commodity e.g. a food product such as peanuts is heat-treated uniformly under precisely controlled conditions.