Hypochlorous acid (HOCl) is a harmless disinfectant with excellent sterilizing capability for use in agriculture and food industry. Recently, the use of non-diaphragm electrolytic cell showed great potential in producing slightly acidic electrolyzed water (SAEW). However, the effect of various physical properties such as electrode gap, flow rate, current, bubble formation and temperature conditions are still under investigation. Herein, we produced 40 ppm SAEW by using a self-developed non-diaphragm electrolytic cell using 6% HCl. The tested range of electrolyte flow rate was 2-4 mL/min and current was 10-15 A. The results indicate that bubble generation by increased current decreased the average convection heat transfer coefficient between the electrode and electrolyte resulting in increased temperature. Hence, an optimized flow rate of 3 mL/min at 13 A current were best process conditions. Finally, SAEW showed excellent sanitization against various Escherichia coli concentrations.