A study was carried out on yeast fermentation of carica papaya (pawpaw) agricultural waste using dried
active baker's yeast and brewer's yeast strain (Sacchromyces cerevisiae). The pawpaw considered as
an agricultural waste was the tapped ripe pawpaw fruit harvested after the tapping of papain. Effect of
different yeast strains on the percentage yield of ethanol was investigated. The effects of yeast
concentration, saccharification and different nutrient supplements as they relate to the optimization of
the ethanol yield were also carried out. The fermented pawpaw yielded ethanol contents of 3.83 to 5.19% (v/v). The reducing sugar in the pawpaw was determined before and after saccharification. The reducing sugar was highest after 48 h of saccharification using Aspergillus niger. The value recorded
was 7.6 to 13.6 g/100g. Brewers yeast gave a higher ethanol yield than bakers yeast. Saccharification
for 48 h coupled with nutrient supplements significantly increased the ethanol yield.