(Poly-)glycerol partial ester having a number average of 0.75-2.25 acid residues of at least one carboxylic acid with 10-24 carbon atoms and a number average of 0.005-0.5 residues of a polyfunctional carboxylic acid, preferably dimer fatty acids, oxalic acid and fumaric acid, comprises polyfunctional carboxylic acid ester(poly-)glycerol partial ester with a condition that after complete hydrolysis of (poly-)glycerol partial ester, a (poly-)glycerol is obtained, which exhibits a homologous distribution with glycerol, diglycerol, triglycerol, tetraglycerol, pentaglycerol and oligoglycerol. (Poly-)glycerol partial ester having a number average of 0.75-2.25 acid residues of at least one carboxylic acid with 10-24 carbon atoms and a number average of 0.005-0.5 residues of a polyfunctional carboxylic acid, preferably dimer fatty acids, oxalic acid, fumaric acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, malic acid, tartaric acid, tartronic acid, maleic acid, citric acid, phthalic acid, isophthalic acid or terephthalic acid, comprises polyfunctional carboxylic acid ester(poly-)glycerol partial ester with a condition that after complete hydrolysis of (poly-)glycerol partial ester, a (poly-)glycerol is obtained, which exhibits a homologous distribution with glycerol (0.01-20 wt.%), diglycerol (0.01-60 wt.%), triglycerol (0.01-60 wt.%), tetraglycerol (0.01-30 wt.%), pentaglycerol (0.01-20 wt.%) and oligoglycerol (made upto 100 wt.%). Independent claims are also included for: (1) producing the (poly-)glycerol partial ester, comprising (a) providing a (poly-)glycerol, (b) esterifying a part of the (poly-)glycerol with at least one carboxylic acid having 10-24C, and (c) further esterifying with a polyfunctional carboxylic acid, where the molar ratio of the polyfunctional carboxylic acid used in process step (c) to the (poly-)glycerol used in process step (a), is 1:2-1:200； (2) an emulsifie
