Ethanol was produced by fermenting spoilt bananas using Saccharomyces cerevisiae (MTCC183). Total sugar content in banana peels; raw and ripened bananas was estimated by Fehling’s method. Depending on the stage of ripening, banana peels were found to have total sugar content  of 4.07%(v/v) to 7.6%(v/v), while whole ripened bananas were found to have 15.2%(v/v). Saccharomyces cerevisiae (MTCC183) was immobilized in sodium alginate by entrapment method. Viable count of beads was carried out to enumerate number of organisms present. 1 bead contained 9×10⁷cells/ml.

Ethanol production was studied at laboratory scale and bench scale levels. Fractional distillation was carried out to recover the alcohol from the spent fermented broth, while the ethanol content in the distillate was estimated by both dichromate method and specific gravity. Fermentation medium using 100g of spoilt banana yielded 24% to 27 %(v/v) of alcohol. Ethanol yield between free cells and immobilized cell systems was drastically different. Immobilized systems yielded 23% to 27 %(v/v) alcohol while free cell system yielded only 15%(v/v) alcohol. Purity of the distillate was determined using Gas chromatography (FID) and High performance thin layer chromatography. Moisture content in the distillate was determined using Karl Fischer reagent and accounted for 10%.