Tallow is a class of lipids and organic mixture consisting of both saturated and unsaturated fatty acids that can be processed into commercial stearic acid for industrial applications. Stearic Acid can be produced from abattoir by-products (waste animal fats) by fat rendering. Hydrolytic fat splitting (reaction with water) followed by solvent crystallization and purification via distillation of free fatty acid using optimum temperature under application of alkaline catalyst is the commonly used method . After the waste fats were rendered and hydrolyzed in to free fatty acid, characterization of physicochemical properties for both tallow and stearic acid, pattern of triglycerides and fatty acid compositions were done by analytical analysis and using nuclear magnetic resonance (NMR),and Fourier transform infrared spectroscopy (FTIR) instrumental tools. Separation of commercial stearic acid from high crude free fatty acid (tallow fatty acid mixture) using methanol crystallization method was made under the optimal conditions of the fatty acids-to-methanol ratio of 1:15 (w/v), the crystallization temperature of 4 °C, and the crystallization time of 55 minutes and the crystal yield was found to be 80.25% . The effect of three parameters including fatty acid to methanol ratio, temperature and reaction time on the hydrolysis reaction and crystallization was investigated by keeping alkaline concentration (based on fat weight) and 200 revolutions per minute (rpm) stirring rate constant. The physical and chemical properties of produced stearic acid were characterized and determined to be density (0.915 g/cm3), melting point (58 0C), titer point (51 0C), moisture content (0.57%), per oxide value (2.7meq O2/kg SA), ash content (0.25%), saponification value (210.38 mg KOH/g SA), acid value (184.41 mg KOH/g SA) and iodine value (9.19 g I2/100 g SA).