What are patchouli and ylang ylang essential oils made from?

The two oils couldn't be more different in where they come from on their plants, and that difference shapes everything about how they smell and how they're made.

Patchouli: leaves, dried and fermented

Patchouli oil is an essential oil derived from the leaves of the aromatic flowering plant Pogostemon cablin, which belongs to the mint family. Native to tropical Asia, this shrubby perennial grows up to a meter tall, with large, fragrant leaves and small, pale flowers. The essential oil is extracted from the shade-dried leaves through steam distillation. Steam distillation means steam is passed through plant material to carry the aromatic compounds out as vapor, which is then cooled back into liquid form.

What makes patchouli unusual is the curing step. Unlike many essential oils extracted from fresh plants, patchouli requires a "waiting period" known as curing. If distilled immediately after picking, the oil would smell overly "green" and sharp. Harvested leaves are spread under the tropical sun to dry, then gathered into large heaps and covered to ferment. During this time, natural enzymes break down the plant's cellular structure, and chemical precursors convert into the heavy, balsamic notes characteristic of patchouli. Unlike most essential oils, patchouli improves over time, developing smoother and more complex notes as oxidation refines its character.

The best time to harvest the leaves is when the plant hits its six-month maturity. Most of the crop comes from Indonesia, Malaysia and Thailand.

Ylang ylang: flowers, picked at dawn

Ylang ylang is an essential oil derived from the flowers of the tropical tree Cananga odorata. The tree is native to the Indo-Pacific region, encompassing parts of Southeast Asia and Northern Australia. The name comes from the repetition of the Tagalog word "ilang," meaning "wilderness," which is where the tree is naturally found.

Ylang ylang essential oil is created using steam distillation, where steam is passed through the freshly harvested flowers to vaporize the volatile aromatic compounds. Unlike many other botanicals, ylang ylang is typically subjected to fractional distillation, meaning the process is stopped at specific time intervals to collect different grades of oil, distinguished by their changing chemical composition as the distillation progresses. The first fraction collected, called "Extra," has the lightest, most intensely floral scent; later fractions are heavier and more complex.

Harvesters pick the flowers early in the morning, typically between about 7:20 and 7:50 a.m., when the blooms' volatile oil content is at its highest. Worldwide production is relatively low, at around 100 tonnes a year, with 70 tonnes coming from the Comoros alone.

So: patchouli is a leaf oil that gets better the longer you wait, and ylang ylang is a flower oil where timing is everything, right down to the hour of the morning.