The present invention relates to an admixture for mineral binder compositions, especially for concrete, said admixture comprising or consisting of a) at least one kinetic regulator selected from esters of hydroxy carboxylic acid, especially citric acid esters, tartaric acid esters, lactic acid esters, gluconic acid esters, malic acid esters, glycolic acid esters, and/or mandelic acid esters, b) optionally an accelerator for the hydration of cement, and c) optionally water. Admixtures of the present invention reduce the maximum heat flow from mineral binder composition, especially concrete, without unduly retarding setting and/or curing thereof.