cis-3-Hexenol
Leaf alcohol: the specific compound behind the smell of freshly cut grass, and the one a tea maker is judging when they smell a withering trough.
What a drinker notices
- Aroma — an aroma
Freshly cut grass, unmistakably. Clean and sharp at low level, and heavy and raw at high level.
How much of it there is matters: Wanted at low level in a spring green tea and rejected at high level in anything. The transition is narrow enough that a few hours of extra wither can move a batch across it.
What it is
If green-leaf volatiles are a family, this is the member everyone has smelled. It is called leaf alcohol for good reason — it is the dominant note of mown grass and crushed foliage, and it appears in tea leaf within seconds of plucking. In small amounts it reads as freshness and is actively wanted in a first-flush green tea. In quantity it is grassiness. Tea makers assess a wither substantially by nose, and what they are tracking as the smell moves from grass towards flowers is this compound falling while the terpenoids rise.
Chemically: Six-carbon unsaturated alcohol — the archetypal green-leaf volatile.
Where it occurs in the plant
Formed on damage from the leaf's own membrane lipids, so it exists in plucked leaf and not in growing leaf. It disperses steadily through a wither.
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.
- Withering — Lowers it
- Falls steadily through the wither as it disperses, while the floral terpenoids rise. That crossover is what a tea maker is smelling for when they decide the wither is finished.
- Kill-green (fixation) — Locks it in place
- Production stops with the enzymes. A green tea's level is set at fixation and does not change afterwards except by loss.
How brewing brings it out
Extraction rate: Fast — among the first things out of the leaf
Very volatile, out at once in hot water and gone from the cup quickly. It is the first thing smelled and among the first things lost.
Across infusions: Front-loaded and quickly gone. It belongs to the first infusion of a fresh tea and is largely absent by the third.
Water: Sensitive to chlorinated water in the way its whole class is: the fresh green top note is the first thing to go and the body of the cup is unaffected, so a drinker tastes a tea that seems dull rather than one that seems wrong.
Leaf, ratio and agitation: Escapes with the steam. Most of what a drinker gets arrives in the first thirty seconds over an open cup, which is why a lidded gaiwan and a quick pour show it better than a mug that stands.
What you can change
- Let the cup stand briefly if it smells raw
- Brew cooler to extract less of it
Teas this compound defines
Read next
- Green-leaf volatiles — The smell of cut grass, made within seconds of the leaf being damaged, and the aroma most of tea processing exists to get rid of.
- 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 processing that removes it. 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.