Indole
Jasmine at trace level and something much worse above it — the clearest demonstration in tea that dose decides identity.
What a drinker notices
- Aroma — an aroma
At trace level, radiant floral — the lift and carry of a fine jasmine tea. At higher level, heavy, animal and unmistakably unpleasant.
How much of it there is matters: The identity of this aroma changes with dose rather than merely its intensity, which is rare and is why it is the textbook example. A jasmine tea scented too many times, or with too many flowers, crosses the line and cannot be brewed back.
What this gets credited for, wrongly
A heavy, cloying jasmine tea is usually described as over-scented or as low quality. That is right, and this compound is the specific mechanism — not a vague excess of fragrance but one molecule past its threshold.
What it is
Indole is the standard teaching example for concentration-dependent aroma, and tea gives one of its best demonstrations. Dilute, it is intensely floral and is a major part of what jasmine smells like. Concentrated, it is faecal, and it is one of the compounds responsible for that smell in nature. Jasmine flowers emit a great deal of it, so a scented tea carries it, and the difference between a jasmine tea that smells radiant and one that smells heavy is substantially a difference in how much of this single compound went across. It also appears in the leaf's own chemistry during oolong bruising.
Chemically: Nitrogen heterocycle — a bicyclic aromatic amine.
Where it occurs in the plant
Produced by jasmine flowers in quantity and by tea leaf itself during stress and bruising, at much lower levels.
What processing does to it
In tea, processing is not a modifier applied to a fixed composition — it is what decides the composition. These are the steps that move this compound, and each links to the step itself.
- Scenting — Raises it
- Carried across from the flowers with everything else. The number of scenting rounds is a judgement about this compound as much as about the pleasant ones, and more rounds is not straightforwardly better.
- Bruising (shaking) — Raises it
- Produced by the leaf during oolong bruise-and-rest at levels well below the unpleasant threshold, contributing to floral lift.
How brewing brings it out
Extraction rate: Moderate
Volatile and reasonably soluble. Very hot water pushes more of it into the cup, which is one reason jasmine tea is often brewed a little cooler than its base green tea would be.
Across infusions: Present through the early infusions and part of why a heavily scented tea can become unpleasant by the third cup while a well-scented one stays clean.
Water: Not notably water-sensitive. What changes it is concentration: at a heavy leaf ratio the character crosses from floral to animalic, and that is a dose effect in the cup rather than anything the water did.
Leaf, ratio and agitation: The clearest concentration-dependent compound in the catalogue. A gongfu ratio can push a jasmine tea past floral into something drinkers describe as barnyard, using leaf that tastes correct at western strength.
What you can change
- Brew jasmine tea cooler than you would the unscented base
- Keep infusions short
- Judge a jasmine tea on the third infusion, not the first
Where this gets misdescribed
That more scenting rounds always make a better jasmine tea. Beyond a point the flowers keep contributing this compound after the pleasant volatiles have saturated, and the tea gets heavier rather than more fragrant.
Teas this compound defines
Read next
- Jasmine lactone — A creamy, peach-and-jasmine note that arrives in tea both from scenting with real flowers and from the leaf's own chemistry.
- Linalool — A major floral aroma compound of tea, largely stored bound to sugar in the leaf and set free by processing.
What this page does not say
This record describes an aroma compound and the level at which its character changes. It makes no statement about what it does in a body.
Sources
- TeaHQ editorial synthesis — TeaHQ
This page is TeaHQ’s own synthesis of well-established tea chemistry. No external technical document stands behind it, and that constraint is why there are almost no numbers here: directions, rankings and mechanisms are stated plainly, quantities are not, because a figure nobody can check would look more authoritative than it deserves.