Mathematical Model for Assessing Wort Filtration Performance Based on Granularity Analysis

A laboratory filtration system equipped with a 0.80 mu m nitrocellulose membrane for wort filtration and a 0.45 mu m mixed cellulose ester microporous membrane for beer filtration was used for this study. The critical granularity distributions of wort and beer before and after filtration were determined by the Beckman Coulter Multisizer 3 counter and particle size analyzer. Using Matlab 7.0 software, a mathematical model of the wort filtration performance and granularity relationship was established, which is applicable for predicting and improving the wort filtration performance. The granularity distribution and percentages of particle numbers and volumes of the wort before and after filtration had great impact on the wort filtration performance. The percentages of particle numbers and particle volumes were used to characterize the wort filtration performance based on a mathematical model. The correlation between real and predicted wort filtration performance values was very close. R-2, the relative error of real value and prediction value on wort filtration performance, was defined as (predicted value - real value)/real value. When we used the particle number percentage, a relative variation R-2 was between 1.67 and 3.01%. When we used the particle volume percentage, the relative variation R-2 was between 2.89 and 3.87%.