Growth dynamics of lactic acid bacteria (LAB) of the culture Fresco DVS 1010 and Lactobacillus rhamnosus GG in milk- and water-based amaranth mashes with sucrose or flavouring compounds (chocolate, caramel) were evaluated in this study. After fermentation that was performed at 37 ± 1 ℃ for 8 h in CO2 incubator (5 %) the products were kept at 6 ± 1 ℃ for 2 weeks. The content of proteins, lipids, reducing sugars, and starch of used amaranth flours was determined before and after expiry date, to evaluate the differences in main nutritional components. The results showed that all amaranth substrates were suitable for fermentation as the LAB levels from 108 to 109 CFU · ml-1 were reached and the levels higher than 106 CFU · ml-1 remained during cold storage. The presence of milk compared to water had no significant impact on the growth rates of LAB under study. Sensory value of flavoured amaranth mashes after the 8 h fermentation, and after 7 and 14 days of refrigerated storage was part this study as well. The best sensory acceptance according to the final evaluation of overall acceptability was evaluated in case of milk amaranth chocolate mash after 7 days of storage.