This study explores the potential of oil palm empty fruit bunch (OPEFB) as a valuable resource and employs early batch fermentation as an evaluation method. Gluconic Acid (GA) and Xylonic Acid (XA) are organic acid that can be generated by Gluconobacter oxydans simultaneously under aerobic condition. Utilizing a 10% (v/v) inoculum, Gluconobacter oxydans is utilized to convert glucose and xylose present in the medium, under controlled conditions of 30°C, 220 rpm, no aeration, and pH 6. Data collection is conducted at 0-6 hours. Two growth media, synthetic and OPEFB hydrolysate, are employed. Synthetic medium contained 41.52 g/L glucose and 18.91 g/L xylose, while the hydrolysate had 2.20 g/L glucose and 3.80 g/L xylose. Fermentation was carried out in 100-mL erlenmeyer flask. The results demonstrate that the hydrolysate medium achieves higher gluconic acid productivity at t=2 h, while the synthetic medium yields the highest xylonic acid productivity at the same time. Notably, the hydrolysate medium did not produce xylose during early batch fermentation. A fermentation process strategy is required to produce XA, not only GA, as OPEFB is a feedstock that is highly prospective for mass production. Additionally, G. oxydans has been demonstrated to be capable of synthesizing both GA and XA simultaneously. © 2025 Author(s).