The present invention relates to low-foam surfactant mixtures comprising esters of the general formula (I) and alcohols thereof of the general formula (Ia) where R is a branched or unbranched alkyl radical having from 8 to 22 carbon atoms; Ra, R1 are each independently hydrogen or a branched or unbranched alkyl radical having from 1 to 5 carbon atoms; R2 is a branched or unbranched alkyl radical having from 5 to 17 carbon atoms; l, n are each independently from 1 to 5 and m is from 38 to 70, and where the ratio of the molar amounts of the esters (I) to the alcohols (Ia) is at least 17:3. The invention further relates to the process for preparing them and to their use and to washing and cleaning composition formulations comprising them.