The interfacial area for a liquid-liquid system has been determined by the chemical reaction method. The saponification of butyl formate ester with 8 M sodium hydroxide has been used to this end. A correlation has been derived to describe the mole flux of ester through the interface and the kinetic rate constants have been calculated. For a continuously operated reactor a correlation has been derived for both reaction in the dispersed phase as well as reaction in the continuous phase. A viscosity factor had to be incorporated to obtain one single correlation for the Sauter mean drop diameter. The validation for this chemically enhanced reaction regime is presented and discussed.