NOVELTY - A recyclable esterification or transesterification catalyst comprises porous particles that have a composite matrix of mesoporous silicate and alkaline earth metal oxide moieties. The catalyst contains both acidic and basic sites and has a surface area of greater than 50 m2/g.    USE - The recyclable esterification or transesterification catalyst is used to prepare biodiesel or methyl soyate (claimed).    ADVANTAGE - The catalysts are solids that function as heterogeneous catalysts that can be easily separated from a reaction mixture; are easily recycled for use in subsequent catalytic reactions; are stable even after repeated usage; and have very high surface areas due to their porosity. The pores are large to allow passage of vegetable and animal oils and alcohols used in the transesterification process, and can be chemically modified to allow more rapid passage of certain large molecules. The catalysts rapidly and under mild conditions convert vegetable and animal oils to 10-30C alkyl methyl esters and glycerin, which are easily mechanically separable.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) a method for transesterifying an ester to provide 1-4C alkyl ester comprising combining the ester, 1-4C alcohol, and the catalyst that catalyzes the formation of 1-4C alkyl ester of the acid portion of the ester and the corresponding free alcohol of the ester;    (2) a method for preparing fatty acid 1-4C alkyl esters from a feedstock that comprises fatty acid glycerol esters and fatty acids comprising combining the feedstock, 1-4C alcohol, and the catalyst that catalyzes the formation of the corresponding fatty acid 1-4C alkyl esters;    (3) a method for producing fatty acid 1-4C alkyl ester comprising combining a glyceride-containing vegetable or animal oil, 1-4C alcohol, and the catalyst that catalyzes formation of corresponding fatty acid 1-4C alkyl ester and glycerol;    (4) a method for producing methyl soyate comprising combining soybean oil, methanol, and the catalyst that catalyzes formation of glycerol and methyl soyate; and    (5) a method for preparing a mesoporous silicate alkaline earth metal oxide composite-based catalyst comprising combining 8-22C alkyl-tri(1-3C)alkylammonium halide, solvent, and base to form a first mixture; heating the first mixture; combining the first mixture with a tetra(1-4C)orthosilicate and an alkali metal oxide or alkali metal hydroxide, to provide the catalyst in a second mixture; recovering the mesoporous catalyst from the second mixture; and heating the catalyst to 100-600degreesC.    DESCRIPTION OF DRAWING(S) - The figure is a graph showing the catalytic conversion of soybean oil and poultry fat into biodiesel.