Colloidal stability is still to be one of the critical challenges facing the brewing industry. In brewing, chemical, physicochemical, enzymatic and mechanical methods are widely used to increase the colloidal stability of beer. The physicochemical method is based on the use of stabilizers to remove colloids such as proteins and polyphenols that enter the beer from raw materials such as malt, unmalted grains and hops. The most widely used products today are silica gel for protein stabilization and polyvinyl polypyrrolidine (PVPP) for polyphenol stabilization. In Russia, the silica gel of foreign brands is widely used in brewing as an adsorbent for proteins (30-50 g / hl), which leads to a rise in production costs. Since any company strives to produce quality products at lower production costs, the ability to use domestic products in production that allows achieving the desired goal, rather than foreign (imported) products, is considered one of the preferred ways to reduce costs. In this regard, the aim of the study is to investigate the adsorption capacity of some brands of silica gel produced in Russia and their effectiveness in increasing the colloidal stability of beer. For the study, 4 samples of silica gel were proposed: three samples of domestic and one of a foreign brand “Stabifix’’. Samples of Russian-made silica gel corresponded to GOST 3956-76 “Technical silica gel. Technical conditions’’.
Beer was stabilized with silica gel of different samples at the rate of 30 g / hl of beer calculated on ADB. The efficiency of the process of removing protein colloids was assessed by the turbidity of the beer and the indicator “limit of protein precipitation by ammonium sulfate’’. it was found that all samples have practically the same sorption capacity.
The best results were obtained in the beer treated with silica gel of the “Stabifix’’ brand (H90 = 0.133 EBC units) and “xerogel’’ of domestic production (H90 = 0.137 EBC units). All beer samples treated with silica gel had a high protein precipitation limit of 26 ± 1 ml, which corresponds to shelf life of at least 3 months. This conclusion is confirmed by the results obtained during the artificial ageing of beer. The method used assumes alternating temperatures of 60 ° C and 0 ° C. At each of these temperatures, the beer is thermostated for 24 hours. The turbidity of the beer is measured after each cooling operation. Measurements are carried out until the turbidity value reaches 2 EBC units. One day of ageing at 60 ° C corresponds to one month of storage of beer without the appearance of turbidity. It was found that all beer samples subjected to artificial ageing after 3 cycles of temperature alternation of 60 ℃ / 0 ℃ had practically the same turbidity, the value of which ranged from 2.29 to 2.41 EBC units in the experimental samples and 2.49 in a control sample of beer with silica gel “Stabifix’’. On the basis of laboratory studies, the promise of using silica gel “xerogel’’ of domestic brands, which in their adsorption properties are not inferior to foreign ones, have been proved.
|Publication||Without publication of the article|
|Affiliation of speaker||ITMO University|