Influence of different lengths and vinification yeast strains on the subsequent conduct of malolactic fermentation

The topic of this bachelor thesis is to determine individual organic acids, specifically tartaric, malic and lactic acids in grape must after a final fermentation using high performance liquid chromatography. The reason behind examining the levels of organic acids are various microbiological conditions of fermenting musts with the subsequent influence on the sensoric quality of the resulting wines. In the theoretical section we describe the technological processing of grapes during wine making, characterize the anatomical and chemical structure of the used grapevine, grape microbiota and its influence on the process of organic acid transformations. Separate chapters are dedicated to specific species of the yeasts Saccharomyces cerevisiae, Torulaspora delbrueckii and bacteria Oenococcus oeni for their fundamental place in the fermentation process. The influence of this microbiota is evaluated in the practical section, where the records of individual inoculations are noted and the fermented musts are analyzed using the separational method of high performance liquid chromatography. The levels of organic acids and the length of fermentation gives evidence of the influence of the participating microbiota on the length of wineification and the physico-chemical parameters of fermentation. For the general assesment of efficiency of the used microbiota on individual fermentatated musts, a sensoric evaluation of samples is conducted