Due to its high FFA content, cod liver oil may require acid esterification (using H₂SO₄) before base-catalyzed transesterification with NaOH or KOH. A two-step method is most effective. For cleaner oil, base catalysis alone suffices. The GlobeCore USB plant supports both acid and base catalysis, with automated control of reaction stages, methanol ratios, and catalyst dosing, making it ideal for processing marine oils like cod liver. Enzymatic transesterification is also an option for small-scale, high-purity applications but is costlier.