The invention relates to a method for lowering the viscosity of a fat based mixture comprising solids and fat that have been previously refined to a powdery mass characterized in that the powdery mass is submitted to elongational flow effective as such to provide breaking up of the agglomerates and intimate interactions of the solids with the fat thereby resulting in the production of a pasty mass with coating of the solids with the fat. The method enables to replace conching in a traditional conche or at least reduce conching time or increase the subsequent loading and throughput of the fat based mass in traditional conches.