Abstract: A method of tempering edible fatty compositions such as chocolate comprises controlling the temperature of the composition to a predetermined temperature, passing the temperature-controlled composition continuously through a heat exchanger, cooling the composition, monitoring the consistency of the composition, and using the results to control the cooling of the composition in the heat exchanger, the monitoring being effected by measuring the pressure difference across the heat exchanger using pressure transducers, measuring the load on a motor used for mixing or stirring the composition in the heat exchanger, or by measuring the viscosity of the composition with an in-line viscometer.

Abstract: An extrusion die for producing hollow extrusions from material which is difficult to solidify quickly, e.g. chocolate, the die comprising an outer die part secured to the end of a supply pipe, a central aperture in the outer die part within which an inner die part having a multiplicity of spaced air injectors is provided, so that during extrusion chocolate forced through the apertures surrounds the injectors to produce an extrusion product having a plurality of longitudinal passages therein. A fluid, e.g. air, is passed through the injectors and into the longitudinal passages to prevent collapse of the passages before the chocolate has set. Relative rotation between the outer and inner die parts may be effected.