Mash separation in the Lauter Tun - A particle size dependent separation process

Lautering is a solid liquid separation in the brewhouse for which the dominant filtration mechanisms are still unknown. The wide particle size distribution of the involved solids leads to the hypothesis that during lautering different particle size fractions are experiencing different filtration mechanisms. To investigate this matter sedimentation behavior, particle size distribution in the lautering filter cake, and the concentration of free fatty acids were analyzed. It can be shown that coarse particles (> 500 μm) are forming a cake by sedimentation whereas fine particles (< 500 μm) are experiencing a cake filtration on top of this sediment and colloidal particles such as fatty acids are separated by depth filtration.