20.500.12556/RUL-125995 Vpliv različnih dejavnikov na potek fermentacije in nekatere kakovostne parametre piva The influence of different factors on the course of fermentation and some quality parameters of beer Namen diplomskega dela je bil preučiti vpliv različnih dejavnikov, ki vplivajo na potek fermentacije in kakovost piva. Spreminjali smo količino ekstrakta v osnovni sladici, vrsto kvasovk in njihovo količino ob inokulaciji ter izbirali med dvema temperaturama, pri kateri je potekala fermentacija. Poskus smo izvajali v treh paralelkah, od katerih smo eno analizirali že po nekaj dneh, ostale pa na koncu. Ugotavljanje vpliva dejavnikov na kinetiko fermentacije smo spremljali gravimetrično z večkratnim vmesnim tehtanjem. Ugotovili smo, da na kinetiko vplivajo vsi parametri, najbolj opazen pa je vpliv temperature. Stopnjo navideznega ekstrakta smo merili direktno v pivu, količino pravega ekstrakta pa z refraktometrom po destilaciji v destilacijskem ostanku. Z destilacijo vzorcev smo dobili tudi destilat, v katerem smo izmerili stopnjo alkohola. Na podlagi teh analiz smo ugotovili, da na prevrelost in stopnjo alkohola v pivu najbolj vpliva temperatura v kombinaciji z uporabljenim sevom kvasovk. Za ugotavljanje vrednosti FAN in grenčice v pivu smo uporabili referenčne metode. Te so pokazale manjši vpliv spremembe dejavnikov, od katerih je najbolj izstopala uporaba različnih kvasovk. S poskusom smo ugotovili, da lahko s spremembo kritičnih dejavnikov v procesu pridelave piva bistveno vplivamo na končni produkt. The purpose of this diploma thesis was to study the influence of various factors affecting the fermentation process and the quality of beer. We were changing the original extract, the type and quantity of yeasts at inoculation, and the temperature under which fermentation took place. The experiment was carried out in three parallels, one of them was analysed after a few days and the other two were analysed in the end. The determination of the influence of different factors on fermentation kinetics was monitored gravimetrically by multiple intermediate weigh-ins. We found out that the kinetics was affected by all parameters, with the influence of temperature being the most obvious. The amount of apparent extract was measured directly in the beer, meanwhile the real extract was determined with a refractometer after distillation in the distillation residue. By distilling the samples we also obtained a distillate in which the alcohol content was determined. Based on these analyses, we found out that the amount of residual sugars and alcohol level in beer are most affected by the temperature in combination with the yeast strain used. To determine the value of FAN and bitterness in beer, we used reference methods. These showed less influence of the applied factors, of which the use of different yeasts stood out the most. The experiment demonstrated that the change of critical factors in the process of beer production can significantly affect the final product. pivo kakovost piva fermentacija temperatura kvasovke ekstrakt v osnovni sladici določanje stopnje alkohola določanje pravega ekstrakta določanje grenčice določanje prostega aminokislinskega dušika kinetika fermentacije beer quality of beer fermentation temperature yeasts base wort extract determination of alcohol degree determination of the real extract determination of bitters determination of free amino acid nitrogen fermentation kinetics true false false [G. Korat] Slovenski jezik Angleški jezik Diplomsko delo/naloga 2021-04-11 07:15:03 2021-04-11 07:15:17 2022-09-05 03:53:30 0000-00-00 00:00:00 2021 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 663.45:543.2/.9 191092 60019715 12202.pdf 12202.pdf 1 67406584EAE7DEEB0644B4E8F601090F 82d4806b537dbdda034cb2e26a0a3653fbf3d76409d2467542a4aee96142cf02 d4390c19-a1bb-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=141867 Biotehniška fakulteta 0 0 0