The present invention relates to the field of food industry, where it may be used for producing alcoholic products, to pharmacology for producing infusions tinctures and extracts or preparations containing aqueous-alcoholic solutions as pharmaceutically acceptable media and also to cosmetology for producing cosmetic products containing aqueous-alcoholic solutions as cosmetically acceptable media. In the proposed process for preparing an aqueous-alcoholic solution, separation of harmful admixtures takes place due to the preliminary protonation separately of water and alcohol prior to the formation of the aqueous-alcoholic solution, this leading to improvements in the physicochemical and organoleptic characteristics of the final product. The process not only provides the possibility of preparing alcoholic beverages of improved quality, but also to shorten the production cycle in the case of preparing some of them (by as much as two times and more) and, as a consequence, to cut down the product costs.