This work details a parametric study of a laboratory-scale, novel stirred, multistage, countercurrent extractive reactor called the basket impeller column (BIC), as applied to the production of biodiesel. Waste frying oil was used as the feed, aqueous solutions of ethanol as the solvent and coreactant, while Candida antarctica lipase B immobilized on macroporous acrylic resin (Novozym 435) catalyzed the ethanolysis reaction. The effects of key operating parameters on the performance of the BIC, including stirring speed, the solvent-to-feed ratio (S/F), the solvent ethanol concentration (C-EtOH,C-sol), and the number of stages, were investigated with the objective of guiding process optimization. The BIC operated under conditions of low Damkohler number (Da <= 0.25) and the combined diffusional and reaction resistances in the organic phase appeared to be rate-limiting. A moderate stirring speed of 500 rpm was optimal for yield, while S/F had only a minor influence on BIC performance. Increasing the C-EtOH,C-sol value from 20% (v/v) to 60% (v/v) had a dramatic effect, with an almost complete loss in yield, attributable to severe, permanent catalyst deactivation. Yield was proportional to the number of stages in the BIC, because of the associated rise in reactor space time and the Da value, with respect to key reactants.