Brewing performance evaluation of Saccharomyces cerevisiae strains isolated from Ethiopian traditional fermented beverages

The growing customer demand for diversified brewery products is pushing the brewery industry to search for brewer's yeasts. The aim of this study was to screen and evaluate the brewing potential of eight S. cerevisiae strains isolated from Ethiopian traditional fermented beverages. They were screened for potential brewer's yeast characteristics, and then their brewing performance were evaluated on a laboratory scale. Screening data indicated that all strains demonstrated reasonable brewing characteristics. Brewing performances evaluation has shown that tested strains showed reasonable performance. They yield ethanol content ranging between 5.2 +/- 0.2 and 5.5 +/- 0.2 (v/v%) with degree of attenuation varying between 64.1 +/- 6.8 and 72.6 +/- 2.0%. Compared to the investigated strains, the commercial strain showed remarkable performance with ethanol production (6.1 +/- 0.2, v/v%) and attenuation degree (82.2 +/- 2.0%). Produced beers were analyzed for sensorial attributes, and they were not statistically significant in all tested sensorial profiles, except beers produced by MABD1 and Sc. JD9, which were recognized as extremely bitter by two tasters. FT-IR spectra matching of experimental and reference beers revealed that beer samples exhibited the same spectral pattern, implying they have a similar chemical profile. Studies focused on the understanding of the determinant abiotic factors for an acceptable performance of the investigated S. cerevisiae strains at the simulated industrial-scale brewing condition is recommended. Moreover, adaptation to maltose and malto-dextrin assimilation at low temperature condition is recommended.