The present invention provides a method to prepare a fatty acid lower alkyl esters from a feedstock, such as a vegetable or an animal oil, comprising one or more fatty acid glycerol esters such as mono-, di- or tri-glycerides, and free fatty acids, comprising combining the feedstock, a lower alcohol and an acidic mesoporous silicate under conditions wherein the mesoporous silicate catalyzes the formation of the corresponding fatty acid lower alkyl ester of the free fatty acids an optionally glycerol.