Monitoring of the mashing process by viscosity measurements

Technical Session 17: Mashing Session
Simon Henke, TU München - Chair of Process Engineering of disperse Systems, Weihenstephan
Co-author(s): Jens Voigt and Karl Sommer, TU München, Chair of Process Engineering of Disperse Systems, Weihenstephan, Germany

ABSTRACT: During mashing the conversion of starch to fermentable sugars is the most important result. Over the last decades brewhouse technology and malt quality have improved substantially, so mashing time is very short. Nevertheless the success of mashing is controlled mainly after the mashing procedure by an iodine test or laboratory analysis of the Congress wort. A proper in-line measurement hasn’t been established. A procedural approach gives the opportunity to control the mashing procedure in-line. The measurement parameter of the presented method is the viscosity of the mash suspension. The viscosity is a sensitive parameter that shows changes in the fluid phase of the mash as well as in the disperse phase of the mash. A torque measurement of the agitator in the mash tun provides the data to calculate suspension viscosity. With this measurement and further knowledge about the performance characteristic of the agitator, the development of mash conversion is detectable. A thoroughly developed performance characteristic is independent of the test suspension and only has to be acquired once. This work gives detailed information about the experimental way to set up the required power characteristic and the resulting viscosity calculation. The presented procedure is possible for every agitator system independent of its scale. Different experiments were conducted varying the grinding parameters and water/grist ratio. The influence of these parameters was monitored by the viscosity measurements and is presented in this work. The gelatinization point, as well as the saccharification of the mash, were detectable. So, the measurement technique offers an easy way to better understand and control mashing procedures.

Simon Henke graduated from Technical University Munich in 2009 with an engineering degree in brewing sciences and beverage technology. In 2010 he started his work at the Chair of Process Engineering of Disperse Systems, TU Munich, as a research associate. His fields of activity are mass transport phenomena and procedural aspects of the mashing process. He is responsible for the pilot plant brewery at the Chair of Process Engineering.