A process for preparing a nonionic surfactant includes the steps of: cleaving at least one of the isopropylidene groups of an isopropylidene polyglycerol C.sub.6 -C.sub.22 -fatty acid or mono- or polyhydroxy fatty acid ester, by hydrolysis or ketal exchange, in the presence of acid, at a temperature in the range of about 20.degree. C. to about 100.degree. C., and at atmospheric, reduced or superatmospheric pressure, thereby regenerating hydroxyl groups on the polyglycerol; and recovering the resultant polyol ester nonionic surfactant. Such polyol ester surfactants are useful as emulsifiers, especially for preparing skin care or cosmetic formulations and paints and wood-preservation agents.