An interdigital mixer-redispersion capillary assembly was applied to prevent the liquid-liquid bubbly flow coalescence in microreactors. The redispersion capillary consisted of 1-mm-long 0.25 mm inner-diameter constrictions, placed every 0.50 m along the channel length. The system was tested on the phase transfer-catalyzed esterification to produce benzyl benzoate. The application of constrictions to prevent coalescence resulted in a better reproducibility and higher conversion compared to a capillary without constrictions. The bubbly flow generated by the interdigital mixer-redispersion capillary assembly was found to be independent of the redispersion capillary inner diameters (0.50 and 0.75 mm) while being highly dependent on the flow rates. By controlling the total flow rate and the aqueous-to-organic ratio, the bubbly flow surface-to-volume ratio could be increased up to 230 700 m(2)m(-3). Compared to the conventional phase transfer-catalyzed esterification, the continuous operation in the interdigital mixer-redispersion capillary assembly eliminated the use of solvents and bases, removing an energy-intensive step of distillation while increasing process safety.