The impact of microorganisms on barley and malt quality | Mikroorganizmi u pivarskim sirovinama tijekom slađenja

English. Microorganisms are inevitably present in barley, malt, wort, and sometimes in finished beer. They are the cause of numerous problems in the brewing industry. Microbial colonization of barley occurs already in the field during the vegetation transition of barley. The microflora on barley and the malt obtained from it affects numerous aspects of the quality of the production process in malthouses and breweries and on the quality of the finished beer. In addition, the presence of microbial contamination on barley results in the formation of antimicrobial compounds, the presence of which indicates stress during the vegetative period of barley cultivation caused by microbial contamination. If they survive the wort brewing process, these compounds can have negative or positive effects on the further production process and on the finished beer. Furthermore, the microorganisms present on barley can themselves produce antimicrobial compounds against other microorganisms that can also affect the yeast and the malt and beer production process itself. This paper provides a basic overview of the influence of barley microflora on the malting process and malt quality, wort production and its quality, the fermentation process and its influence on the activity of brewer's yeast and on the final product, beer.

Croatian. Mikroorganizmi su neizbježno prisutni u ječmu, sladu, sladovini, a ponekad i u gotovom pivu. Uzročnici su brojnih problema u pivarskoj industriji. Mikrobna kolonizacija ječma javlja se već u polju tijekom vegetacijskog perioda ječma. Mikroflora na ječmu i od njega dobivenog slada utječe na brojne aspekte kvalitete samog proizvodnog procesa u sladarama i pivovarama i na kvalitetu gotovog piva. Osim toga, prisutnost mikrobne kontaminacije na ječmu rezultira stvaranjem antimikrobnih spojeva, čija prisutnost ukazuje na stres tijekom vegetacijskog perioda uzgoja ječma uzrokovanog mikrobnom kontaminacijom. Ako prežive proces kuhanja sladovine ovi spojevi mogu imat negativne ili pozitivne učinke na daljnji proces proizvodnje i na gotovo pivo. Nadalje mikroorganizmi prisutni na ječmu mogu i sami proizvoditi antimikrobne spojeve protiv drugih mikroorganizama koji također migu utjecati i na kvasac i na sam proces proizvodnje slad i piva. U ovom radu dan je osnovni pregled utjecaja mikroflore ječma na proces slada i kvalitete slada, proizvodnju sladovine i njezinu kvalitetu, proces vrenja i utjecaja na aktivnost pivarskog kvasca te na konačni proizvod, pivo.