In this study, three batch tests were conducted to investigate the effect of total solids loading, substrate to inoculum ratio, and fermentation temperatures on mixed-acids (total volatile fatty acids, TVFA) production from food waste (FW). Results showed that adding anaerobic inoculum could largely increase the extent of acidification of FW. Temperature could significantly influence the mixed-acids yield. Increasing S/I (substrate to inoculum ratio (on volatile solid basis)) ratio from 3 to 9 resulted in lower TVFA yields. The highest TVFA production with a concentration of 18.4 g/L (as acetic acid) was found at 6.0% TS (total solid) loading, 3 S/I ratio, and 37 degrees C.