AN APPLICATION OF CLASSICAL AND INSTRUMENTAL METHODS OF ANALYSIS IN QUALITY CONTROL OF BEER

In order to control the quality of beer and raw materials for production of beer in Belgrade Beer Industry (BIP), water is analyzed (city, technological and demineralized water). Measurements of pH values indicated the increased pH values in the sample of tehnological water, which had no impact on wort hopping, since the tested samples of wort, young beer and final product had a pH value within the expected range. After processing city water, a sample of tehnological water was found with increased carbonate hardness, which is caused by the increased content of sodium hydrogen carbonate. Analysing the titration alkalinity, titration acidity and buffering power, it was found that the alkalinity was decreasing which is in accordance with the determination of pH values of wort and beer samples (young beer and final product). Analyzing the content of anions and cations in the examined water samples, it has been shown that the concentration of these examinated anions (Cl^–, NO^3 –, SO4^ 2– and PO4 ^3–) and cations (NH4^ +, Na^+, K^+, Ca^2+, Mg^2+) are within the limits prescribed by the Regulations on hygienic safety of drinking water, and thus by the Regulations of quality and other requirements for beer. The contents of anions in wort and beer samples (young beer and final product) were determined by ion chromatography method. The contents of sulphate and nitrate ions were within the recommended limits. The concentration of chloride ions was above 150 mg/dm^3, which may have an impact on the sensory properties of beer, while changes in the content of phosphate ions were insignificant.