Isolation, identification and screening of high-quality yeast strains for the production of milk beer

The aim of this study was to screen yeast strains from kefir grains for good fermentation abilities to produce milk beer. Molecular identification tests revealed the 17 yeast strains isolated belonged to four different species [Kluyveromyces marxianus (4/17), Pichia kudriavzevii (6/17), Dekkera anomala (1/17), Kazachstania unispora (6/17)]. Through physical and chemical testing of the 17 fermentation sample strains, five strains met the standard for milk beer production. Of the five strains, three strains showed better characteristics based on sensory evaluation and volatile components analysis. Based on principal component analysis, strain MJ1 (K.marxianus) performed the best and was deemed the most suitable for milk beer fermentation.