The invention relates to a stirring mechanism (90) for a machine for preparing chilled or frozen products comprising one motor, the stirring mechanism (90) comprising one or a plurality of transmission paths between an input shaft (94) rotatable at a speed ωin by the motor and an output shaft (98) rotatable at a speed ωout, the transmission paths providing different values of the ratio ωin/ωout and being selectable as a function of the direction of rotation of the input shaft (94). The invention further relates to a machine (100) for preparing chilled or frozen products comprising a stirring mechanism (90) as described, the stirring mechanism (90) entraining in rotation stirring means (9) to prepare the product. Even further, the invention relates to a system comprising such a machine (100) and a container (10) comprising the ingredient or ingredients for preparing the product by the rotation of the stirring means (9).
