In a method for making a tris-(2-hydroxyethyl)-methylammonium methylsulfate fatty acid ester by quaternizing a tris-(2-hydroxyethyl)-amine fatty acid ester with dimethylsulfate the quaternizing is carried out in the presence of a solid acid scavenger. The method can provide a fabric softener active composition, comprising from 65 to 98% by weight of at least one tris-(2-hydroxyethyl)-methylammonium methylsulfate fatty acid ester, the corresponding non-quaternized tris-(2-hydroxyethyl)-amine fatty acid esters in amounts providing a total amine number of the composition of from 2 to less than 7 mg KOH/g, and from 1 to 1500 ppm methanol.