NOVELTY - Making one or more bioproducts using quality control, involves: collecting data from one or more continuous processes to produce one or more bioproducts, where the data set comprises (a) conversion data for one or more feedstocks to fatty acid methyl esters, (b) catalyst aging, (c) feedstock selection, (d) reaction product composition, (e) by-product composition, (f) quality of at least one of the bioproducts, or (g) combinations.    USE - The method is useful for making one or more bioproducts (claimed), e.g. petroleum based diesel and lubricants.    ADVANTAGE - The method provides a continuous process for making fatty acid alkyl esters, and can efficiently transesterify both edible and non-edible vegetable oils in refined or unrefined forms at mild conditions. It can also be used in simultaneously converting free fatty acid contaminants of naturally-derived and sustainably-produced fatty acid glycerides at mild conditions, and enables economic benefits and makes the bioproducts an economical alternative to petroleum based diesel and lubricants.    DETAILED DESCRIPTION - Making one or more bioproducts using quality control, involves: collecting data from one or more continuous processes to produce one or more bioproducts, where the data set comprises (a) conversion data for one or more feedstocks to fatty acid methyl esters, (b) catalyst aging, (c) feedstock selection, (d) reaction product composition, (e) by-product composition, (f) quality of at least one of the bioproducts, or (g) combinations, where the at least one of the feedstocks comprise one or more fatty acid glycerides and/or one or more alcohol; and adjusting one or more parameters of the continuous process based on the collected data to maintain or adjust a quality of at least one of the bioproducts produced. An INDEPENDENT CLAIM is included for a system of continuous manufacture of fatty acid alkyl esters, which comprises: at least one mixing device for mixing one or more alcohol compounds and one or more feedstocks, where the feedstock comprises one or more fatty acid glycerides and one or more free fatty acids; a reactor, the reactor being capable of receiving a flow from the mixing device; at least one analyzer coupled to the reactor, where the analyzer measures concentrations of a reaction mixture in the reactor, and where the reaction mixture comprises one or more compounds of the feedstock, one or more fatty acid alkyl esters, glycerin, or mixtures; a device coupled to the reactor, where the device allows a sudden drop in pressure to induce removal of one or more of the alcohol compounds and/or water from the reaction mixture; and a separator coupled to the device, the separator capable of separating the glycerin from the one or more fatty acid alkyl esters.