An anti-foam additive for a cement composition, including a fatty alcohol ester that is soluble in an aqueous medium at acidic pH, and hydrolysable in a basic medium, i.e. when the ester is incorporated into the cement composition, while releasing an active anti-foam molecule. This ester is preferably a fatty alcohol ester of a quaternary ammonium carboxylate, that is soluble in an aqueous solution of a superplasticizer, such as a polycarboxylate with poly(ethylene oxide) side chains. The additive can used for reducing the amount of air entrained during mixing or blending of mortars or concretes.