A method for producing polyglycerol esters of polycarboxylic acids esterified with oxobutanol, especially mono- or polyvalent polyglycerol esters of polycarboxylic acids esterified with 4-oxo-4-(C 1 -C 5 -alkoxy)-2-butanol or with 4-oxo-4-(hydroxy-C 3 -C 5 -alkoxy)-2-butanol, wherein (i) at least one oxobutanol, especially 3-hydroxybutanoate, preferentially 4-oxo-2-butanol, preferably 4-oxo-4-(C 1 -C 5 -alkoxy)-2-butanol or 4-oxo-4-(hydroxy-C 3 -C 5 -alkoxy)-2-butanol, of the general formula CH 3 -CH -CH 2 -C OR 1 wherein, in the general formula, the radical R 1 represents C 1 -C 5 -alkyl or hydroxy-C 3 -C 5 -alkyl, especially ethyl, butyl, pentyl, hydroxybutyl or hydroxypentyl, preferably ethyl, hydroxybutyl or hydroxypentyl, more preferably ethyl, (ii) at least one polycarboxylic acid, especially at least one polycarboxylic acid comprising at least two carboxyl groups, wherein the polycarboxylic acid is used in the form of the free polycarboxylic acid, in the form of a salt of the polycarboxylic acid, in the form of a polycarboxylic acid ester or in the form of the polycarboxylic acid anhydride, and (iii) at least one polyglycerol are reacted and/or caused to react with one another, wherein the method is carried out in one step or else in several steps, and wherein the method is carried out in the absence of solvents and/or without any solvent, and wherein, when the polycarboxylic acid is used in the form of the free acid, water is formed simultaneously during the reaction, wherein the water is continuously withdrawn from the reaction; and/or wherein, when the polycarboxylic acid is used in the form of the anhydride, the corresponding free polycarboxylic acid and water are formed, wherein the resulting free polycarboxylic acid is further reacted or, after the reaction has taken place, is removed and optionally recycled and wherein the water is continuously withdrawn from the reaction; and/or wherein, when the polycarboxylic acid is used in the form of the ester, the corresponding ester alcohol and water are formed, wherein the resulting ester alcohol and water are continuously withdrawn from the reaction, so that, as a reaction product, one or more polyglycerol esters of polycarboxylic acids esterified with oxobutanol, especially one or more polyglycerol esters of polycarboxylic acids esterified with 4-oxo-2-butanol, preferentially one or more mono- or polyvalent polyglycerol esters of polycarboxylic acids esterified with 4-oxo-4-(C 1 -C 5 -alkoxy)-2-butanol or with 4-oxo-4-(hydroxy-C 3 -C 5 -alkoxy)-2-butanol, are obtained. (i) at least one oxobutanol, especially 3-hydroxybutanoate, preferentially 4-oxo-2-butanol, preferably 4-oxo-4-(C 1 -C 5 -alkoxy)-2-butanol or 4-oxo-4-(hydroxy-C 3 -C 5 -alkoxy)-2-butanol, of the general formula CH 3 -CH -CH 2 -C OR 1 wherein, in the general formula, the radical R 1 represents C 1 -C 5 -alkyl or hydroxy-C 3 -C 5 -alkyl, especially ethyl, butyl, pentyl, hydroxybutyl or hydroxypentyl, preferably ethyl, hydroxybutyl or hydroxypentyl, more preferably ethyl, (ii) at least one polycarboxylic acid, especially at least one polycarboxylic acid comprising at least two carboxyl groups, wherein the polycarboxylic acid is used in the form of the free polycarboxylic acid, in the form of a salt of the polycarboxylic acid, in the form of a polycarboxylic acid ester or in the form of the polycarboxylic acid anhydride, and (iii) at least one polyglycerol are reacted and/or caused to react with one another, wherein the method is carried out in one step or else in several steps, and wherein the method is carried out in the absence of solvents and/or without any solvent, and wherein, when the polycarboxylic acid is used in the form of the free acid, water is formed simultaneously during the reaction, wherein the water is continuously withdrawn from the reaction; and/or wherein, when the polycarboxylic acid is used in the form of the anhydride, the corresponding free polycarboxylic acid and water are formed, wherein the resulting free polycarboxylic acid is further reacted or, after the reaction has taken place, is removed and optionally recycled and wherein the water is continuously withdrawn from the reaction; and/or wherein, when the polycarboxylic acid is used in the form of the ester, the corresponding ester alcohol and water are formed, wherein the resulting ester alcohol and water are continuously withdrawn from the reaction, so that, as a reaction product, one or more polyglycerol esters of polycarboxylic acids esterified with oxobutanol, especially one or more polyglycerol esters of polycarboxylic acids esterified with 4-oxo-2-butanol, preferentially one or more mono- or polyvalent polyglycerol esters of polycarboxylic acids esterified with 4-oxo-4-(C 1 -C 5 -alkoxy)-2-butanol or with 4-oxo-4-(hydroxy-C 3 -C 5 -alkoxy)-2-butanol, are obtained.