The machine comprises a cylindrical working tub, a mixer body (5) mounted to rotate inside the working tub around an axis of rotation, and a motor unit (6) mechanically joined to the mixer body for rotating around the rotational axis. The motor unit is provided with a motor shaft, which is protruding from the bottom of the working tub by maintaining coaxial to the axis of rotation. The mixer body is movable and structured to fit on the free end of the shaft, and comprises a first hub (7) and a second hub (8) aligned on the motor shaft one above the other. The machine comprises a cylindrical working tub, a mixer body (5) mounted to rotate inside the working tub around an axis of rotation, and a motor unit (6) mechanically joined to the mixer body for rotating around the rotational axis. The motor unit is provided with a motor shaft, which is protruding from the bottom of the working tub by maintaining coaxial to the axis of rotation. The mixer body is movable and structured to fit on the free end of the shaft, and comprises a first hub (7) and a second hub (8) aligned on the motor shaft one above the other. The first hub is aligned to rotate freely on the shaft resting on the bottom of the working tub, and mechanically joined to the working tub to remain immovable during the rotation of motor shaft. The second hub rotates along with the motor shaft in angular plane so as to rotate inside the working tub around the axis of rotation. The mixer body is further provided with many blades, which protrude from the first hub, many radial support arms, which protrude in the radial direction of the second hub surrounding the blades, and a series of scraper spatulas that are conveniently distributed on the radial arms to rub according to the position on the bottom or on the cylindrical side wall of the working tub. The blades are two flat protruding appendices, which protrude in the radial direction of opposite sides of the first hub, and the remaining are coplanar with the pos
