I get this question often.
Essential oils come from, and are distilled in, dozens of countries around the world. It is a science and art unto itself. Like wine and coffee, essential oils have optimal growing regions as well as harvesting and distillation methods in order to obtain optimal chemical constituents. It is hugely complex and requires pounds and in some cases tons, of plant material.
Rose absolute, for instance, can come from Bulgaria, Morocco and Russia. Lavender can come from France, Bulgaria, Italy, and USA. And there can be more than one region in a particular country where it is grown. Some of those regions produce different botanical species with different chemical constituents. Some producers harvest and distill with more care. Some plants are wild-crafted, some organic, some are commercial enterprises with distillation taking place with material from various farms in a particular region, with lots of farmers bringing their product to be distilled.
Producing essential oils is a massive undertaking. For instance, one liter of jasmine absolute requires 8 million hand-picked jasmine blossoms at the perfect time of bloom, hence, it’s high price.
My area of expertise is knowing the regions that produce the best essential oils, knowing how they should smell and the knowledge to formulate the essential oils for optimal results.