Device for preparing a frozen food product from a liquid mixture and a method for operating the device

A device for preparing a frozen food product from a liquid mixture, the device, comprising:

• a cup holder comprising a cavity for releasable receiving a cup in which the frozen food product is to be prepared from the liquid mixture in an operational phase of the device;
• a cooling unit configured for cooling the cavity of the cup holder in the operational phase;
• a stirring unit configured for stirring the liquid mixture in the cup with a stirring element in the operational phase for preparing the frozen food product, wherein the stirring unit comprises a drive system for driving a stirring motion of the stirring element in the cup with a motor;
• a control unit configured for operating the device, wherein the control unit is at least operatively connected to the cooling unit and to the motor of the drive system of the stirring unit;
• and
• a torque sensor configured for measuring a torque applied by the motor,
• wherein the control unit is further operatively connected to the torque sensor,
• wherein the control unit is configured for:
• starting the operational phase of the device by activating the cooling unit for cooling the cavity of the cup holder, and by activating the motor for driving the stirring motion of the stirring element in the cup;
• monitoring, in a first period of the operational phase between the start of the operational phase and a predetermined first time, with the torque sensor, the torque applied by the motor for driving the stirring motion of the stirring element in the cup, and determining a linear increase of the torque monitored in the first period;
• monitoring, after the first time, with the torque sensor, the torque applied by the motor for driving the stirring motion of the stirring element in the cup, and if with respect to the linear increase of the torque determined in the first period an increase above a predetermined threshold occurs in the torque monitored after the first time, then initiate a termination phase for ice cream, otherwise initiate a termination phase for sorbet.