Abstract: Raw coffee beans or nuts are put in a revolving drum divided into at least four independant modular sectors each of which carries a given quantity of the product through a succession of similarly independent work stations to be heated, roasted, cooled and discharged ultimately through an outlet. The air used to cool the product is recycled from the roasting station, being drawn from the drum into a separator, freed of any skins or husks that may be entrained from the roast, then directed into a cooling system that lowers its temperature to sub-ambient level before returning it to the drum; the option exists of enriching the recycled air with additional aromas before it finally enters the cooling station.