In order to optimise the process of fining beer there is a need to model the process in terms of addition, mixing and flocculation. Mixing of beer and finings has been achieved in a small laboratory stirred vessel that enables exact characterisation of the shear conditions and residence time. The performance of the finings was evaluated after settling in Imhoff cones. Results identified an optimum mixing regime comprising two stages; a relatively vigorous and short duration first mix followed by a longer more gentle mix.

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 .

Previous work has identified the optimal two-stage static mixing process for a small-scale pilot rig. Protocols for scale-up to any brewery process line have been specified. A full-size prototype has been installed in a cask ale brewery. In most cases superior product clarity was obtained when the prototype was operated. Unexpected further benefits were demonstrated from mixing downstream of the mixing system and also disturbance and subsequent resettlement in the cask.