Two yeast isolates, one from teff dough and another from tella, out of total fifty isolates were screened and identified through morphological and physiological tests and found Saccharamyces species. They were compared with the commercial baker’s yeast, in terms of biomass production and leavening capacity. Their biomass was compared with respect to molasses concentration, pH, incubation temperature and period. All isolates showed maximum yield at 8% w/v molasses concentration. The three isolates differed in their biomass yield at various pHs, whereas all isolates gave highest biomass at thirty degree centigrade. Addition of supplements to the molasses medium showed 1.5- 2 fold increase in biomass. Concerning leavening action, the commercial isolate was superior. Generally, the commercial yeast was better in terms of biomass yield, whereas dough isolate was superior with respect to leavening action. Tella isolate was still competent. Further studies on molecular properties of these yeasts could improve their performance in biomass propagation and leavening action. This book assesses all these and is useful for academicians, researchers, yeast production and bakery industries.