CHARACTERISTICS OF SINGLE AND MIXED CULTURE FERMENTATION OF PITO BEER

The fermentation of Pito, a traditional alcoholic beverage, was done using selected yeast strains or a crude mixed yeast culture collected from traditional breweries and two types of sorghum malt. The fermentation characteristics and product quality of the pure and mixed fermentations were monitored and compared. Significant differences were observed between the mixed culture fermentation and the single culture fermentations. Acid production of the mixed culture fermentations was higher whereas ethanol production and sugar utilisation were lower than those of the pure strain fermentations. Sensory observations and analysis of volatile compounds also indicated differences in the fermentations. The use of pure cultures in fermentations proved to yield more ethanol. The sorghum variety was also observed to have an influence on the fermentation pattern. Utilisation of nutrients from the white sorghum malt extract was greater and faster than those from the red sorghum.