The base catalyzed alcoholysis of vegetable oil is a common industrial process for the production of biodiesel. The performance of the methanolysis reaction could be improved by applying continuous processes and using microreactors because of the strong mass transfer limitation of this react ion. This limitation is often neglected for the base catalyzed ethanolysis reaction. The KOH catalyzed ethanolysis of soybean oil was carried out in continuous and in batch. The experimental results and kinetic modeling of the data show strong mass transfer limitations of the reaction. The limitation is reduced by increasing the efficiency of micromixing which leads to performances exceeding the batch process under otherwise identically reaction conditions. (C) 2013 Elsevier Ltd. All rights reserved.