The work investigates the influence of temperature on the reaction kinetics and the consequent change in the distribution of homologues during ethoxylation of fatty acid methyl esters. It was found that temperature-related kinetics of ethoxylation significantly affects the composition of the products and more narrow distributions of homologues are found with an increase in the reaction temperature from 135degreesC to 185degreesC. It is suggested that intermolecular complexation of the catalyst cation takes place, thus broadening the distribution of the homologues produced at the lower temperature range and the effect decays with increases in the reaction temperature. The substantial influence of the distribution of homologues on the products' viscosity and solubility is revealed.