An experimental study was conducted to optimise the production of rice bran biodiesel by the bubble wash method. Biodiesel was produced by both transesterification and purified methods (bubble wash and transesterification) separately for alcohols, such as ethanol and methanol, with the presence of KOH as the catalyst. The purified method has improved the yield of rice bran biodiesel with the lesser consumption of alcohol and catalyst when compared with the transesterification method. The maximum yield of biodiesel for the rice bran ethyl and methyl ester was 92.5% and 90.5%, respectively, by the transesterification method and 94.9% and 91.4%, respectively, by the bubble wash method. So, the purified method resulted in the significant yield of biodiesel.