Diafiltration of mash

Lautering is a critical step in the production of wort because of its impact on both the quality and yield of the collected wort. Lautering comprises two unit operations: the removal of suspended particles from the wort and the extraction of the soluble extract remaining in the solid phase and in the surrounding liquid phase. New developments in lautering techniques allow for the segregation of the above two steps and provide the opportunity to find an optimum technical solution for each operation. The desire to replace the conventional lauter tun by a resilient, specialised, separation technique e.g. a dynamic microfiltration, requires an appropriate extraction process: diafiltration. A mathematical description, in conjunction with experimental data, can explain the difference between diafiltration and conventional extraction by means of a cake filter sparging system. The impact of the technical parameters on the extract yield, derived from theoretical and experimental results, indicate that a high concentrating degree and a small mashing liquor ratio are important preconditions for high extraction efficiency.