TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The final transesterification stage is continued until the fatty acid monoglyceride content of the fatty ester stream has fallen below 0.8 (preferably 0.4) wt.%. The final thermal treatment is continued until the water content of the fatty ester stream has fallen below 0.05 (preferably 0.02) wt.%. The alcohol stream containing glycerol resulting from any stage of the alkali-catalyzed transesterification is used for pretreating the fatty acid glycerides. The residue resulting from the step of removing the alkyl alcohol, comprises less than 2 (preferably 0.5) wt.% of the monovalent alcohol. The monovalent alcohol evaporate is recycled to the transesterification step, without further rectification. The thermal treatment comprises maintaining the fatty ester stream, washed residue, washed fatty acid monovalent 1-5C alkyl esters with a cold soak filtration test time according to ASTM D 6217 of at least 200 seconds or the fatty acid monovalent 1-5C alkyl esters with a cold soak filtration test time according to ASTM D 6217 of at least 200 seconds, within a temperature of 100-180 degrees C. The thermal treatment comprises subjecting to microwave radiation or ultrasonic acoustic waves. The thermal treatment is performed under autogenous pressure or reduced pressure. The fatty ester stream, washed residue, washed fatty acid monovalent 1-5C alkyl esters with a cold soak filtration test time according to ASTM D 6217 of at least 200 seconds or the fatty acid monovalent 1-5C alkyl esters with a cold soak filtration test time according to ASTM D 6217 of at least 200 seconds, is maintained at reduced pressure after reducing the temperature below 150 degrees C. In the process, antioxidant and/or metal deactivator is blended in the fatty ester stream, washed residue, washed fatty acid monovalent 1-5C alkyl esters with a cold soak filtration test time according to ASTM D 6217 of at least 200 seconds or the fatty acid monovalent 1-5C alkyl esters with a cold soak filtration test time according to ASTM D 6217 of at least 200 seconds, prior to and/or after the step of subjecting to thermal treatment. EXAMPLE - A sample was prepared by adding 0.05% Filtracel EFC-250-C (RTM: Extract free cellulose) as body feed and the sample was allowed to equilibrate at 5 degrees C above its cloud point (+5 degrees C for soybean oil sample) for 12 hours under gentle agitation (120 rpm). Then the sample was vacuum filtered in a Buchner flask over Whatman 1 filter paper. The centrifugated at 5500 rpm for 15 minutes at 20 degrees C and the supernatant was decanted. Then biodiesel (500-1000 ml) was distilled in a laboratory deodorizer at 180 degrees C, 3 mbar and 0.5-1% steam injection during 30-60 minutes. Then subjected to thermal treatment consists of applying vacuum of 200 mbar and heating the sample from 60-150 degrees C during 6 minutes by submerging the flask in a pre-heated bath of thermal oil, allowing an isothermal period at 150-155 degrees C for 4 minutes, releasing vacuum and cooling the sample from 150 degrees C to 60 degrees C by submerging the flask into a bath of cold water to give SBME1 sample with cold soak filtration test time of 161 seconds.