Reference point
Lightly crushed fresh perilla leaves.
Do this before you read on. An entry only works when you have just smelled the thing.
Green but warm — two qualities that rarely go together. Under the green there is a very faint cinnamon note that no other herb has, and a slightly pungent finish at the end of the breath.
Set it next to Vietnamese coriander and you see it at once: perilla is round and closed, Vietnamese coriander edged and open. It is the best contrasting pair in the green family, because the two herbs so often appear together on the same table.
Purple and green perilla differ in intensity rather than in nature. The purple leaf is stronger and more pungent, which is why the north prefers it in rice porridge for colds.
How to smell it
Crush a fresh perilla leaf in your palm and smell at once. Then crush a leaf of Vietnamese coriander in the other hand and smell the two in turn. Comparing directly between two hands works much better than smelling them a few minutes apart, because the nose adapts very quickly.
Why this one is hard
The cinnamon note in perilla is very faint and only shows when you already know to look for it. It is a textbook example of vocabulary coming before perception: read the word cinnamon and smell again and you catch it; smell before reading and you usually miss it.
Don’t confuse with
This entry
Perilla leaf
Green family
Perilla is round and warm; Vietnamese coriander is edged and has a fatty note from straight-chain aldehydes.
This entry
Perilla leaf
Green family
Lolot is thick and dark, with a peppery, earthy note; perilla is lighter, with a faint cinnamon note and a pungent finish.
This entry
Perilla leaf
Green family
Vietnamese balm has a cool, minty note running over the top that perilla lacks entirely.
Scientific note
Perillaldehyde makes up most of perilla oil and hardly occurs in significant amounts in any other species. It is one of the few cases where a single compound is distinctive enough to serve as a marker for identifying the species. A derivative of it, perillartine, is used as a sweetener in Japan and is about two thousand times sweeter than sugar.
In Vietnamese life
In Vietnamese meals perilla almost always accompanies something fishy or cooling: snails, fish, rice porridge for colds. The pairing repeats often enough to form a lasting association, and for many people the smell of perilla immediately brings to mind the feeling of being ill.