The present invention relates to a method for the preparation of a treated zeolitic material having a BEA framework structure including the steps of: (i) providing a zeolitic material having a BEA framework structure, wherein the BEA framework structure includes YO2 and X2O3, wherein Y is a tetravalent element, and X is a trivalent element, and wherein the zeolitic material having a BEA framework structure is obtainable and/or obtained from an organotemplate-free synthetic process; (ii) calcining the zeolitic material provided in step (i) at a temperature of 650° C. or more; and (iii) treating the calcined zeolitic material obtained from step (ii) with an aqueous solution having a pH of 5 or less, as well as to zeolitic materials per se preferably obtainable according to the inventive method and to their use, and to a process for converting oxygenates to olefins employing the inventive zeolitic materials.