Reference point
Cut a ripe passion fruit in half and smell the pulp.
Do this before you read on. An entry only works when you have just smelled the thing.
Sour, sweet, and with a clear sulphur note that no other fruit in this family has.
That sulphur note sits close to raw onion or grapefruit, and it is why passion fruit divides people: some find it tropical, others slightly unpleasant. Both are smelling exactly the same thing.
It also lasts longer than most fruit in the family. Hands that have touched passion fruit pulp still smell of it after washing.
How to smell it
Cut it in half and smell straight into the pulp. Then put a little pulp on the back of your hand, leave it for five minutes and smell again — the sourness has gone, the sulphur has stayed. That is the lesson: two speeds in one fruit.
Why this one is hard
Because the sulphur part leaves people stuck for a name. It is unlike any other fruit, so there is no ready word, and people borrow “strong” — a word about intensity, not about character.
Don’t confuse with
This entry
Passion fruit
Citrus family
Both are rich in esters. Passion fruit has a sulphur layer that jackfruit lacks entirely; jackfruit is dense and evenly sweet.
Scientific note
Passion fruit contains a group of volatile sulphur compounds, among them thiols and sulphides at parts-per-billion concentrations. Their detection thresholds are extremely low, so they dominate the whole impression while making up only parts per ten thousand by weight. It is the clearest example in the citrus family of trace components deciding the character.
In Vietnamese life
Passion fruit came to Vietnam from South America in the colonial period and is now grown widely in the Central Highlands. It is one of the few fruits whose juice, jam and seeds are all used.