Reference point
Crushed fresh pandan leaves.
Do this before you read on. An entry only works when you have just smelled the thing.
Almost identical to freshly cooked sticky rice, plus a green layer from the fresh leaf.
This pair is the clearest proof of something counter-intuitive: smell does not belong to the species, smell belongs to the molecule. Two organisms far apart on the family tree can still make the same compound, and when they do, they give the same smell.
Understanding this is a turning point in how you read every analysis from then on. The list of components matters more than the species name, and two different species with the same list will smell alike whatever plant family they belong to.
How to smell it
Crush a fresh pandan leaf and smell it. Straight afterwards lift the lid of a pot of sticky rice and smell. The overlap is the shared molecule; the difference is the green layer only a fresh leaf has. This exercise takes one morning and teaches more than a chapter of a book.
Why this one is hard
Not hard for the nose, but hard for the mind to accept. Many people object that the two are obviously different — and they are right: they differ in the secondary layer and are alike only in the main one.
Don’t confuse with
This entry
Pandan leaf
Gourmand family
Almost the same molecule. Pandan has an extra green layer from the fresh leaf; sticky rice has an extra milky note.
Scientific note
Both sticky rice and pandan leaf contain 2-acetyl-1-pyrroline, a small nitrogen-containing molecule the human nose detects at extremely low concentrations. The two species are not closely related: one is a grass, the other a tropical plant. That they both make the same compound is convergent evolution at the molecular level.
In Vietnamese life
Pandan leaves are used to boost the smell of ordinary non-glutinous rice, a trick common throughout Southeast Asia. It is really the addition of a missing molecule — aromatic technique in the true sense, practised in home kitchens for generations before it had a name.