Flat
A verdict about absence: the aromatics are gone and nothing has replaced them. Not a sensation, and still a fault.
A flat cup is not unpleasant, it is uneventful. The aroma has faded, the finish stops at the swallow, and nothing develops across infusions. It is a judgement assembled from absences rather than a sensation, which is why it sits on the same axis as complexity — the two are the poles of the same non-sensory verdict. The commonest cause is age in the wrong direction: green and lightly oxidised teas lose their volatiles over months, faster if stored warm, in light, or in something that breathes. Vacuum-sealed sencha kept in a freezer holds for a season; the same tea in a tin on a sunny shelf is flat by the end of it. The second commonest is water — very soft or deionised water gives a curiously hollow cup from leaf that is perfectly good. Naming it matters because a drinker whose tea has gone flat usually blames the brewing, and brewing is the one thing that will not fix it.
Which sense this is
Not a sensation. A judgement about a tea rather than a sensation in it. Recorded here so that it can be told apart from the sensations, not because it is wrong to say.
A verdict, not a sensation — nothing detects an absence, and it is noticed by what fails to arrive. Recorded on the `not_sensory` axis alongside complexity, and recorded as a fault, which is why the axis and the fault vocabulary are separate fields rather than one.
Evaluative judgement. A verdict about the tea as a whole rather than a sensation within it. Legitimate to say, and not a sensory descriptor.
Where it comes from
- Processing step
Aromatic loss over time, accelerated by warmth, light, air and moisture. Green and lightly oxidised teas lose the most and lose it fastest, which is the whole argument for cold storage of Japanese green tea.
A named production step reliably produces it. A statement about practice, not about chemistry.
Types: type-green-tea, type-oolong-tea.
- Brewing variable
Very soft, deionised or repeatedly boiled water gives a hollow cup from sound leaf. Mineral content in the water is part of what the extraction is working with.
Produced at the drinker's end, by a brewing choice or a brewing error.
When it is a fault, and when it is not
A fault wherever it appears. Distinct from a tea that is delicate by design: delicacy has a finish and develops across infusions, and flatness is the absence of both.
Not to be confused with
- Complexity (Not a sensation) — A verdict about a tea rather than a sensation in it — recorded here so it can be told apart from the sensations.
What gets said that is not right
That a flat cup can be brewed back. More leaf and longer steeping make a stronger flat cup; the aromatics that left are not coming back.
Nearby
A tasting note is a comparison, not a measurement. Where the route from leaf to sensation is established it is labelled as such above; where it is not, the page says so rather than supplying a mechanism the descriptor has not earned. See the rest of the vocabulary for how the axes divide up.