TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The process of producing methyl ester comprises: reacting a first fat with a first quantity of methanol in the presence of a first quantity of a catalyst to produce a reaction product that comprises an alkyl ester and glycerol; contacting the reaction product with a triglyceride-containing second fat to yield an intermediate product; separating the intermediate product into a methyl ester-rich fraction and a glycerol-rich fraction; and contacting the methyl ester-rich fraction with a second quantity of methanol and a second quantity of the catalyst, where the second quantity of methanol comprises no greater than 14 wt.% of the combined weight of the second fat, the second quantity of methanol, and the second quantity of the catalyst; and the first quantity of methanol comprises 13-22 wt.% of the combined weight of the first fat, the first quantity of methanol, and the first quantity of the catalyst. The reaction product is a first reaction product, where the methyl ester-rich fraction is a first methyl ester-rich fraction, and the glycerol rich fraction is a first glycerol-rich fraction. The process further comprises: reacting the second quantity of methanol with at least the second fat to produce a second reaction product; and separating the second reaction product into a second methyl ester-rich fraction and a second glycerol-rich fraction, where the second methyl ester-rich fraction has a lower glycerol content than the first methyl ester-rich fraction. The process comprises: settling the first reaction product into a methyl ester-containing layer and a glycerol containing layer; decanting the glycerol-containing layer; mixing a second charge with the first product; and performing a second transesterification reaction after mixing the second charge with the first product. The process comprises mixing the second charge including mixing a second triglyceride-containing fat with the first triglyceride-containing fat, before the settling and decanting processes. The step of mixing the second charge includes introducing additional alcohol to the reactor after decanting the glycerol-containing layer. The additional alcohol is 90-100% of a stoichiometric amount needed to transesterify a triglyceride-containing fat in the second charge. The method further comprises determining an end point of the first transesterification reaction before settling the first product based on at least one of a reaction time, a composition of the first product, and an appearance of the first product. The process further comprises removing the second glycerol containing portion from the second methyl ester-containing portion and receiving a third triglyceride-containing fat into the second methyl ester-containing portion and reacting the first, second, and third triglyceride-containing fats with the alcohol. The step of reacting the first and second triglyceride containing fats includes producing mono-acyltriglyceride and di-acyltriglyceride in a transesterification reaction, and where the method further includes removing mono-acyltriglyceride and di-acyltriglyceride from the second methyl ester containing portion with the second glycerol-containing portion and moving reaction equilibrium of the transesterification reaction toward methyl ester. The step of reacting the first and second triglyceride containing fats includes producing free fatty acid and/or soap, and the process further includes removing the produced free fatty acid and/or soap from the methyl ester-containing portion with the second glycerol-containing portion. Preferred Components: The first and second fats comprise the same fat, which is a vegetable oil or an animal fat. The first and second fats comprise a vegetable oil or an animal fat, but the first fat is different from the second fat. The first and second fats comprise a vegetable oil and the other of the first and second fats comprise an animal fat. The first alcohol in the first charge is in excess of a stoichiometric amount needed to transesterify the triglycerides in the first fat. The weight of the first alcohol in the first charge is at least 3 wt.% greater than a stoichiometric amount needed to transesterify the triglycerides in the first fat. The weight of the second alcohol is not greater than a stoichiometric amount needed to transesterify the triglycerides in the second fat. The weight of the second alcohol is less than 3 wt.% greater than a stoichiometric amount needed to transesterify the triglycerides in the second fat. The weight of the second alcohol is less than the stoichiometric amount. The second alcohol comprises methanol and the weight of the second alcohol is not more than 11 wt.% of the combined weight of the second fat, the second alcohol, and the second catalyst. The first and second alcohols each comprise methanol, the first alcohol comprises 13.5-20 wt.% of the first charge, and the second alcohol comprises no more than 11 wt.% of the combined weight of the second fat, the second alcohol, and the second catalyst. The ratio of the weight of the first fat to the weight of the second fat is 6:1-1:2, preferably 3:1-1:1. In the process, at least one of the first fat and the second fat has an acid value of at least 2. The first and second triglyceride-containing fats include at least one of soybean oil, tallow, rapeseed oil, palm oil or corn oil. The feed storage is adapted to hold a triglyceride-containing first fat and a triglyceride-containing second fat that differs from the first fat. EXAMPLE - A first charge including tallow (2854 g, acid value (AV) of 1.1, methanol (621.6 g) and sodium methoxide (24.4 g, 30% methanol solution) was added to a round bottom flask fitted with agitation, nitrogen purge, condenser, and heating. The reactants were mixed and heated to 65 degrees C with agitation and nitrogen purge and then held for 6 hours. After 6 hours, a sample of the mixture was allowed to settle in a separate container into an upper methyl ester-rich layer and a lower glycerol-rich layer. The methyl ester-rich upper layer contained mono-acylglyceride (MAG) (0.554%), di-acylglyceride (DAG) (0.235%), unreacted tri-acylglyceride (TAG) (0.064%), total glycerol (0.186%) and 6.6% volatile. The agitation was stopped and the mixture allowed to separate. After 1 hour, the crude glycerol was removed, leaving a crude methyl ester as a first reaction product. The first reaction product (2034.8 g), soybean oil (911.09 g), methanol (91.1 g) and sodium methoxide (18.1 g) were added to the flask, heated to 50 degrees C with agitation and nitrogen purge, and then held for 4 hours. After, the agitation was stopped, the mixture was settled and then split. The recovered glycerol was removed. The excess methanol in the retained product was distilled off at 80 degrees C. After distillation, the mixture was cooled, neutralized and washed with phosphoric acid (3 g) and water (31 g). The mixture was settled, split and washed again with water (31 g), and split. The batch was heated under vacuum and agitation to 90 degrees C. After half an hour it was cooled and filtered to give methyl ester product containing MAG (0.731%), DAG (0.782%), TAG (0.063%), free glycerol (0.034%) and total glycerol (0.314%).