The most commonly used method for biodiesel production is transesterification, a process in which vegetable oils (triglycerides) react with alcohol (usually methanol) to generate fatty acid mono-alkyl esters in the presence of alkaline catalysts (usually NaOH or KOH). Transesterification is a reversible reaction; the yield and quality of biodiesel strongly depend on reaction variables such as reaction temperature, reaction time, molar ratio of methanol/oil, and catalyst loading, which can drive the equilibrium toward the product side or vice versa (Ma and Hanna, 1999 and Pullen and Saeed, 2015). As early as the 1980s, Freedman et al. (1984) examined the variables affecting the yields of fatty acid methyl ester (FAME) derived from vegetable oils such as soybean, sunflower, peanut, and cottonseed oil, with or without refining, and provided the most fundamental information. They reported that a molar ratio of alcohol to oil of 6:1 gave optimum conversion to the ester, 1% sodium hydroxide was an effective catalyst, and ester conversions of 96%–98% were obtained by transesterifying refined oils with methanol at 60 °C. Following that, more research that focused on parameter effects and transesterification reaction optimization has been conducted. It is generally believed that temperature and catalyst concentration are the most important factors impacting the reaction, while reaction time and molar ratio of methanol/feedstock oil are less important. Recently, statistical optimization methods such as factorial design and response surface methodology (RSM) have also been employed to optimize transesterification conditions and study the interaction effects among the reaction variables.