The use of Dielectric Barrier Discharge (DBD) cold plasma reactor for biodiesel synthesis in this study is considered effective in eliminating the formation of glycerol. Generally, glycerol is the main obstacle in biodiesel production. With the DBD cold plasma reactor, the field containing a set of high-energy electrons act as an electrocatalyst (plasma driven) in reacting triglycerides and methanol in a mixture of bait oil. This study was meant to determine the effect of temperature on the overall results and characteristics of FAME (Fatty Acid Methyl Esther) or the resulting biodiesel. This synthesis process used castor oil mixed with used cooking oil (palm) and methanol as main reactants without catalysts. Argon gas was used as a plasma carrier gas. The plasma was generated from EPT (Electronic Power Transformer, also called Electronic High Voltage Transformer or Plasmatron, which has a voltage of up to 10 kilovolts (AC). The analytical method used was GC-FAME, GC-MS and FTIR in the determination of the acquisition of methyl esters from triglycerides. The optimum temperature was achieved at 40 °C with biodiesel product yields of 60.71%.