The invention relates to an alcohol-free liquid concentrate for preserving cosmetic products, household products and technical products, which consists of a carboxylic acid component, a stabilizer component, solvents and optionally customary auxiliaries, additives and/or further active ingredients. Here, the carboxylic acid component comprises at least one salt of benzoic acid, propionic acid, salicylic acid, sorbic acid, 4-hydroxybenzoic acid, dehydroacetic acid and 10-undecylenic acid and optionally one or more of said free cards. The stabilizer component comprises substances which, in particular, have a coulour-stabilizing action.