In Practice

German purity law conform stabilisation | Brewhouse Applications / Stabisol

Experiments with the STABISOL process during the past years have let to a large number of observations. However, it is still not possible to give exact advice on the use of STABISOL in an actual case of filtration difficulties in a brewery without preliminary tests. At 0° C, increasing quantities of STABISOL of 25, 50 and 100 ml should be added to the beer to be filtered; after subsequent precipitation and removal of the precipitate, the beer should be tested for filterability.

If STABISOL is not successful at maturation stage, it can also be applied in the brewhouse, especially if high haze lautering is observed. Wort treatment at laboratory scale can give good indication of the efficiancy, that can be expected in the real brewing process. The obvious evaluation criteria is the appearance of the hot wort and the wort during cooling after the separation of the hot trub together with the STABISOL precipitate. In such a case, however, industrial scale tests are the only means of obtaining definitive results since this is the only way to properly record the other production conditions and their influence on the later filterability of a beer. 
It is often observed that beer cannot be filtered brilliantly, even with the finest kieselguhrs. Without any pressure increase the filtrate does not become clearer than 1 - 2, often 3 - 4 EBC units. In these cases an application of 5 - 10 ml/hl STABISOL to the body feed enhances the clarity. The fine haze of the so formed silica gel accomplishes a tighter kieselguhr filter bed. Consequently the clarity amounts to 0,3 - 0,5 EBC and pressure increases with 0,2 - 0,4 bar/h. Some brewers have adopted filtration regimes using coarse particle size DE or filtration aids with reduced surface area and manage the sharpness and differential pressure of the filter through the controlled inline addition of STABISOL