Filtered stillage from the distillation of ethanol made by yeast fermentation of sugarcane molasses, citrus waste, and sweet whey was analyzed by gas chromatography/mass spectroscopy and by high-performance liquid chromatography. Nearly all of the major peaks representing low molecular weight organic components were identified. The major components in cane stillage were, in decreasing order of concentration, lactic acid, glycerol, ethanol, and acetic acid. In citrus stillage they were lactic acid, glycerol, myo-inositol, acetic acid, chiro-inositol, and proline. Finally, in whey stillage the major components were lactose, lactic acid, glycerol, acetic acid, glucose, arabinitol, and ribitol.