In Practice

German purity law conform stabilisation | Application at Filtration

The simplest and most common method is to use STABIFIX stabilisers at the final beer filtration. In this case it can be added directly via the kieselguhr dosing unit. The required rate depends on the desired shelf life. It normally varies between 30 and 100 g/hl, for Stabiclear there would be a limitation of 50g/hl. 
Higher rates of STABIFIX silica gels are needed where beers with high hop rates are to be treated, whilst ordinary lager types need lower rates. As STABIFIX silica gel also acts as a clarifying filter aid, the kieselguhr dosing rate, mainly the portion of fine kieselguhr, can be reduced up to the amount of STABIFIX silica gel added.

The required contact time of STABIFX silica gels with beer is relatively short and usually exists in all common filtration equipments. A longer contact time is can be achieved by dosing the STABIFIX stabilisers from a second dosing unit – for example in the storage cellar – into the beer stream prior to a buffer tank. This would be to the benefit of the Stabiclear (PVPP) performance but is not really necessary for the silica gel products. An extra dosing unit is advisable in those cases where different beers are being filtered and stabilized, because the STABIFIX stabiliser dosage can then be adapted exactly to the beer type and stability requirements without affecting the kieselgur body feed.