The Art and Science of Agarwood Oil Distillation

Hydro Distillation
Traditional producers use Hydro Distillation, a gentle water method that protects aroma. Clean chips are milled or broken and soaked for 1 to 3 weeks, sometimes longer, to soften raw material and open resin pathways. The soaked wood is covered with water and brought to a steady boil in a still. Steam carries fragrant molecules to a condenser, were vapor cools to liquid. The oil separates from the hydrosol and is skimmed in cuts. Long, slow runs and careful soaking improve diffusion and tone, though yield stays modest compared with modern methods. Yield produce during Hydro Distillation varies from 0.15% to 0.25%.

Steam Distillation

This method is used for dry raw material that yield little oil through Hydro Distillation.  Steam Distillation lets professionals extract agarwood oil without direct contact with boiling water.

Chips sit in a sealed chamber while clean steam from a separate boiler raises temperature and pressure. Operators hold pressure for hours, often about 12, so hot pressurized steam penetrate the wood and mobilize resin. A controlled pressure release helps free volatiles. Steam carries them to a condenser, and the oil separates from water. The operating pressure ranges near 80 to 120 psi. Steam Distillation gives agarwood oil a unique smoky aroma. Typical yield production during Steam Distillation is 0.4% to 0.5%.

Supercritical CO₂ Extraction CO₂ above its critical point diffuses like a gas and dissolves like a liquid. Finely ground agarwood is loaded into an extractor and contacted with supercritical CO₂, which pulls aromatic compounds. In a separator, a small change in pressure or temperature releases the extract as CO₂ returns to gas and is recycled. The method runs at low temperature, limits oxidation, and captures heavier chromone derivatives that rarely appear in water distillates causes more yield as compared to other distillation methods. CO₂ Extraction produce yield from 1% up to 1.5%