In selecting a silica hydrogel for beer treatment against chill and permanent haze, the following parameters are important: mean pore diameter, specific surface area and average particle size. A hydrogel has been used which selectively adsorbs proteins principally of 40,000 molecular weight. Trials using lager and ale, including commercial scale operation, have indicated that treatment using 200 to 1,500 ppm has little or no effect on beer flavour, colour, bitterness and head retention but does improve chill stability. Normal commercial treatments for American lager are in the range 320 to 600 ppm (8 to 15 lb/100 US bbl). Successful treatment with hydrogel occurs when it is added as a slurry (i) in the beer line prior to conditioning or aging tank, (ii) to the tank directly, or (iii) prior to powder filtration. The contact time required prior to filtration is a few seconds.
Keywords: beer brewing chillproofing haze silicon dioxide treatment