A kneading channel is provided with an inlet end which is open to receive curd to be kneaded and an outlet end which is open to dispense the curd; a pair of counter-rotating mutually opposite motorized augers, arranged side by side in the kneading channel, move the curd toward outlet end; steam injector elements are opened in the kneading channel; a kneading chamber, which receives the curd from the outlet of the kneading channel, accommodates a motorized spindle with a vertical axis which has rotating arms that cooperate with the fixed arms.