Crude palm kernel oil (CPKO) was converted into its free fatty acids (FFAs) via alkaline hydrolysis. The reaction optimization was performed using Response Surface Methodology (RSM) through D-optimal design to optimize the conducted hydrolysis parameters. The optimization parameters were varied from 1.5 to 2.5 h of reaction time, 50-70°C of reaction temperature, and ethanolic KOH concentration 1-2 M. The highest percentage of free fatty acids was 98 ± 0.7 % with a percentage fatty acid yield of 84.7 ± 0.6 % under optimal conditions, which were 2.16 h of reaction time, 1.77 M ethanolic KOH concentration, and 70°C reaction temperature. High-temperature Capillary Column Gas Chromatography (GC-FID) and Nuclear Magnetic Resonance-Fourier Transform Infrared Spectroscopy (NMR-FTIR) were employed to characterize the product. The physicochemical properties of fatty acids were also tested. The acid value, iodine value, and hydroxyl value of the fatty acids obtained were 275.4 ± 0.7 mg NaOH/g, 21.8 ± 0.2 g I2 / 100 g, and 168.2 ± 0.1 mg KOH/g, respectively.