Method of Converting Free Fatty Acids to Fatty Acid Methyl Esters

A method for converting free fatty acids in acid oil or acid fat into fatty acid methyl esters is disclosed. The method involves adding a small amount of methanol and an acid catalyst to the acid oil or acid fat and subjecting the mixture to conditions that allow the fatty acid methyl esters to form. A lipid phase containing the fatty acid methyl esters and triglycerides can from and be separated from the rest of the reaction mixture. The lipid phase can then be subjected to conditions suitable for converting the triglycerides into fatty acid methyl esters. The method of present invention is especially useful for a process of generating biodiesel using a starting material of vegetable and animal oils and fats that contain a relatively high level of free fatty acids.