Beta zeolite was impregnated with Al(NO3)3, increasing the aluminium content in increments of 0.05%, from 0.00% to 0.25%. A parallel treatment with 0.05% sulphuric acid was also performed; in both cases, methanol was used as solvent (disperse phase). Cation exchange capacity (CEC), ammonia chemisorption, infrared spectroscopy (FT-IR), scanning electronic microscopy (SEM), X-ray powder diffraction (XRD), atomic absorption spectroscopy (AAS), titration with sodium hydroxide and nitrogen physisorption at 77 K were used to carry out the physical and chemical characterization of the catalysts. Furthermore, the catalysts were employed in the esterification of ethanol with acetic acid, to quantify the effect of aluminium impregnation over the beta zeolite.