Microfiltration: A novel technology for removal of trub from hopped wort

Removing hot and cold trub from hopped wort is important, because of yeast viability, beer filtration, quality and fermentation in Membrane Bioreactor. Trub can be removed by several methods, but Crossflow Microfiltration (CFMF) would be an alternative technology. For the filtration a wort was produced. The filtration was performed with the following parameters: temperature (10 +/- 1 degrees C), Transmembrane Pressure (0.4 bar), and Crossflow Velocity (0.4 m s(-1)). Membrane with pore size of 0.2 mu m was applied. The fluxes were determined. Particle size distributions and analytical parameters of samples were measured and retentions were calculated. The initial and steady-state fluxes were 16.75 and 4.89 L m(-2) hr(-1). According to the particle size distributions trub can be removed. Changing of the analytical parameters is appropriate, for example, retention of beta-glucan was 40.17% and Free Amino Nitrogen content did not change. CFMF is an alternative method for removing trub, but the optimization is essential. Practical applications Crossflow Microfiltration (CFMF) would be an alternative and novel technology for removal of hot trub and cold trub from hopped wort and the two processes can be performed simultaneously with the same CFMF equipment. The main advantages of the CFMF are less solid residues, lower energy consumption, lower water requirements, and microbiologically stable product. Our research has several practical applications as mentioned below. First removing at least some hot trub can decrease the production losses and improve yeast viability, beer filtration performance and the quality of finished beer, and removing at least some cold trub can improve yeast viability and the quality of finished beer. Furthermore, if primary fermentation is performed in Membrane Bioreactor (MBR), wort particles (e.g., cold trub) can cause fouling. Finally, it has been proven that hot trub and cold trub can be completely removed by CFMF and the changing of the analytical parameters is appropriate.