A kneading channel (12) is provided with an inlet end (12a) which is open to receive curd to be kneaded and an outlet end (12b) which is open to dispense the curd; a pair of counter-rotating mutually opposite motorized augers (20, 22), arranged side by side in the kneading channel (12), move the curd toward outlet end (12b); steam injector means (32, 34) are opened in the kneading channel (12); a kneading chamber (42), which receives the curd from the outlet of the kneading channel (12), accommodates a motorized spindle (47) with a vertical axis which has rotating arms (48, 50, 52) that cooperate with the fixed arms (58, 60).