Abstract: The invention concerns an apparatus for roasting coffee beans comprising:—a vessel (1) to contain coffee beans,—a heating device (12) to heat coffee beans contained in the vessel,—a control system (180) operable to control the heating device and configured to apply a roasting recipe (R) providing the temperature T@t1, T@t2, . . . to be applied at discrete successive times t1, t2, . . . , respectively, wherein for a customised quantity m of coffee beans introduced inside the vessel,—the control system is configured to obtain at least the quantity m of coffee beans introduced inside the vessel, and—the control system is configured to get access to at least one series of roasting recipes (Ri, Ri+1, . . . ) adapted to the roasting of different successive pre-determined quantities (Mi, Mi+1, . . . ) of beans of same type and to said pre-determined quantities Mi, Mi+1, . . . , and—based on said accessible series of roasting recipes (Ri, Ri+1, . . .