Improving the Effectiveness of Isinglass Finings for Beer Clarification by Optimisation of the Mixing Process. Part 2: Pilot Scale Experiments

Abstract

Previous work in the laboratory identified the benefit of a two stage mixing process after addition of isinglass finings to beer. Static (motionless) mixers have been selected as the mixer of choice for commercial applications. A pilot plant has been employed to identify the ideal quantity and format of mixing elements for each of the two stages. Experiments in three breweries have enabled the optimum mixers to be identified for the pilot rig. Mix quality produced by the static mixers has been measured using a technique called laser induced fluorescence. This information complements the finings performance data. For the pilot plant the optimum first stage mixer had ten mixing elements, and the optimum second stage mixer had a residence time of 1.1 s in the elements at a shear rate of 80–90 s−1.