As mentioned earlier, carrying on the reaction in organic solvent of high alcohol solubility has been suggested as an answer to problem of enzyme inhibition by short-chain alcohols. Although this results in an increased rate of reaction by operating at higher concentrations of alcohol, it is not recommended since it requires additional solvent recovery unit. Supercritical CO2 (SC-CO2) offers the same advantages for lipase catalysis as organic solvents such as solubilization of the alcohol, simple recovery of the enzyme and favoring esterification to hydrolysis. In addition, SC-CO2 offers more, such as product separation and easy recovery of the solvent. Moreover, it is non-flammable, non-toxic and inexpensive. The production of biodiesel in supercritical fluids (methanol) has been reported in the literature; however, just recently the coupled use of lipase with SC-CO2 in the production of biodiesel has been reported (Rathore and Madras, 2007). Using supercritical fluids is usually expensive though, and more work is required in this regard to provide significant enhancement to the production of biodiesel and to offer biodiesel in competitive prices.