The invention relates to a process for lowering the viscosity of a fat based edible material by imparting specific work into the material comprising the steps of: (a) imparting specific work into the material using an energy delivery means (such as a mixer or extruder) operated by one or more control parameter(s), the rate at which specific work is imparted to the material being determined by the one or more control parameter(s)； (b) stopping the energy delivery means from imparting further specific work into the fat based edible material once the viscosity of the fat based edible material reaches a target viscosity (preferably from 2 to 6 Pa.s), where the rate of specific work imparted to the fat based material is determined by setting and/or adjusting one or more of the control parameter(s), to satisfies the relationship given in equation 1: ln η = 0.5919 − 0.4268 ln ω where η denotes the viscosity ratio of the initial to final viscosity of the material and ω denotes ratio a theoretical to actual work imparted to the material. Apparatus and methods using this process are also described.
