hii
the vast majority of true essential oils are produced by distillation
True Steam distillation uses an outside source of steam which pipes the steam into the distillation unit, sometimes at high pressure. The steam passes through the aromatic material, and exits into the condenser.
Hydrodistillation
The botanicals are fully submerged in water, producing a "soup", the steam of which contains the aromatic plant molecules. This is the most ancient method of distillation and the most versatile. It's the method most often used in primitive countries. The risk, of course, is that the still can run dry, or be overheated, burning the aromatics and resulting in an EO with a burnt smell. Hydrodistillation seems to work best for powders (ie, spice powders, ground wood, etc.) and very tough materials like roots, wood, or nuts.
Very delicate aromatics, Jasmine, Linden Blossom,etc. can not survive the process of distillation. To capture their magical aromas, a process of solvent extraction is used.
These are bthe few ways of oil extraction. Kindly let us know for which crop are u looking for and alsothe method of extraction
Ashwini