Flowable food heating with burning prevention

The method prevents or inhibits, during a heating process, burning in a food heating device (20) of a flowable food substance against a heating surface (6) delimiting or contained in a device's cavity (21) that contains the food substance. The heating device comprises an agitator (4) movable in the cavity (21). The method includes the steps of: introducing the flowable food substance into the cavity (21); heating the heating surface (6) and moving the agitator (4) at an agitator speed (41,42) to generate in the cavity (21) a flow of the food substance over the heating surface (6) and in contact therewith; and disturbing the flow of the food substance to break and/or causing asymmetric flow of the food substance in the cavity (21). At a first agitator speed (41) during the heating process, the food substance is caused to flow at different first relative local speeds over the heating surface (6) that includes a first minimum speed location (61) over which the food substance flows at a first minimum speed of the different first relative local speeds. The speed of the agitator (4) is changed during the heating process to a second speed (42), the food substance being caused to flow at different second relative local speeds over the heating surface (6) that includes a second minimum speed location (62) over which the food flows at a second minimum speed of the different second relative local speeds. The second minimum speed location (62) is different to the first minimum speed location (61).