A dispensing apparatus is provided for dispensing a semi-frozen product, such as a semi-frozen comestible or a semi-frozen drink. The dispensing apparatus has at least one freezing barrel defining a freezing chamber. The freezing barrel includes a longitudinally extending inner cylinder and an evaporator disposed about at least a portion of an outer surface of said inner cylinder. The evaporator includes a plurality of channels disposed about the outer surface of the inner cylinder. Each channel defines a heat exchange fluid flow passage through which refrigerant may pass in heat exchange relationship with product in the freezing chamber.
