103. Blocking layers in the lautering filter cake—Influence of particle size and shape

Jörg Engstle (1), Heiko Briesen (1), Petra Först (1); (1) Chair for Process Systems Engineering, Weihenstephan, Germany

Technical Session 7: Brew House Operations
Monday, August 15  •  8:15–9:30 a.m.
Tower Building, Second Level, Grand Ballroom

Problems during lautering are common for brewers. The blocking potential of mash depends on raw materials, process characteristics, and properties of the spent grain cake. Raking knives are used to loosen the cake and to prevent blocking. Nevertheless, raking knives cause a higher turbidity and result in a longer process time. The spent grain cake consists of horizontal layers of different properties. Blocking layers in the cake have been reported in the literature. But today there is no correlation between the blocking potential of certain layers and the composition of these layers. It is known that particle size distribution and particle shape have a large impact on filter cake resistance. Therefore, these parameters have been measured by laser diffraction, dynamic image, and sieve analysis. It can be shown that the particle shape of husks has a high impact on the blocking potential of layers near the false bottom and that particle size dominates the blocking potential of upper cake layers.

Jörg studied brewing and beverage technology in Weihenstephan and received his engineering degree in 2012. Currently he is working on his doctoral thesis at the Chair of Process Systems Engineering in Weihenstephan, Technical University of Munich. His field of research is lautering. His main interests are spent-grain cake structure, differential pressure in lautering and the effect of milieu conditions, such as pH value and ionic strength, on the behavior of fine mash particles.