Research on beer safety and quality

The aim of this work has been to explore the influence of raw materials and technological parameters to safety and quality of beer. Three samples of beer (A, B, C), sorted into various containers (A – glass, plastic and metal, B – glass and plastic; C – metal and glass) were explored. Samples were investigated to determine: - variation of diacetyl concentration; - yeast generation influence to diacetyl formation during technological fermentation process; - the number of late yeast cells in the samples and what influences the number of late yeast cells; - the number of higher alcohols with other fusel compounds and beer safety according to these factors; - quantity of higher alcohols and other fusel compounds in samples acording to the type of containers. It was determined that diacetyl concentration changes differently according to certain types of beer: after 7 days of optimal fermentation the largest diacetyl concentration change was determined in A type of beer (74%), the least change was for B type of beer (46% less than A type of beer and 23% less than C type of beer). It was determined that diacetyl concentration change in beer during fermentation depends on yeast generation. Higher yeast generation requires more time for the diacetyl concentration to normalize. It was determined that longer beer fermentation (C sample - 74,26 (+/- 4,6)) increases the density of beer yeast. Due to shorter fermentation less yeast cells are late: A type of beer – 58,2 (+/- 7,6) %; B type of beer – 62,79 (+/- 5,5) %. The largest higher alcohols and other fusel compounds concentration was found in A type of beer, sorted into plastic and metal containers: 5603,46 ir 5641,67 mg/l, the least higher alcohols and other fusel compounds concentration was found in A type of beer, sorted into glass containers: 864,70 mg/l. It was determined that statistical results about the quantity of higher alcohols and other fusel compounds found in different types of beer, poured into different types of containers, vary statistically reliably (P = 0,0011). And there were no statistically reliable differences in the quantity of higher alcohols and other fusel compounds found in the same type of beer, poured into different types of containers