Method for cleaning a machine for liquid or semi-liquid food products

1. A cleaning method for a machine for processing liquid or semi-liquid products, comprising:

providing a machine including a first container for containing a liquid or semi-liquid basic mixture or finished product; a system for thermal treatment of the liquid or semi-liquid basic mixture or finished product and a mixer,

performing, in time sequence, the following steps:

a) emptying the basic mixture or finished product contained in the first container;

b) washing the first container with a non-pasteurizing washing fluid, including:

a step of filling the first container with the washing fluid, and

a step of emptying the washing fluid from the first container;

c) at least partly filling the first container with a cleaning fluid and subjecting the cleaning fluid in the first container to a pasteurizing thermal treatment;

performing the pasteurizing thermal treatment by recirculating the cleaning fluid contained in the first container by substantially continuously extracting the cleaning fluid from the first container and introducing the cleaning fluid into the first container, thereby making the cleaning fluid travel along a closed path including the first container;

wherein the step c) comprises:

heating the cleaning fluid in the first container;

keeping the cleaning fluid heated in the first container to a pasteurization temperature for a predetermined time;

cooling the cleaning fluid in the first container to a predetermined preservation temperature;

maintaining the cleaning fluid in the first container at the predetermined preservation temperature;

providing the machine with a second container containing a basic mixture and connectable to the first container for feeding basic mixture from the second container to the first container, the second container being deformable to reduce a space occupied by the second container as basic mixture is extracted from the second container;

emptying the basic mixture contained in the second container;

washing the second container with a washing fluid;

at least partly filling the second container with a cleaning fluid;

subjecting the cleaning fluid in the second container to a pasteurizing thermal treatment;

providing that the machine includes a pump for transferring at least one chosen from washing fluid and cleaning fluid between the first container and the second container;

wherein the step of washing the first container and the further step of washing the second container comprise a step of activating the pump to at least partly transfer washing fluid from the second container to the first container;

recirculating cleaning fluid between the first container and the second container by activating the pump at predetermined time intervals to transfer cleaning fluid from the first container to the second container and vice versa, substantially continuously and along a closed path including the first container and the second container.

2. The cleaning method according to claim 1 , wherein the cleaning fluid is water.

3. The cleaning method according to claim 1 , and further comprising performing a cleaning cycle comprising a set of the steps from a) to c) at a predetermined time interval.

4. The cleaning method according to claim 3 , wherein the predetermined time interval is between 65 and 80 hours.

5. The cleaning method according to claim 1 , wherein the step b) of washing the first container with a washing fluid comprises a step of brushing the surface of the first container.