Why the order is usable
The processes that act on stored tea do not run at the same speed. The most volatile aromatic compounds leave first, over weeks and months. Pigment change follows, visible before it is tasted. The slow non-enzymatic darkening and softening of the astringent fraction runs over years. And the lipid oxidation that adds a stale note rather than merely subtracting one arrives later still. Because they are sequential rather than simultaneous, the state a tea is in reports roughly how far along the sequence it has travelled — which is not the same as how old it is, since the rate depends entirely on conditions. What this method gives is therefore a position rather than a date, and that is usually the more useful of the two. A tea that has spent one year in a warm damp kitchen and one that has spent four in a cool sealed tin may be at the same point, and for every decision a drinker has to make about them they are the same tea. The Sprint 31 storage-chemistry page sets out the mechanisms; this page uses them backwards, as a diagnostic on a packet with nothing written on it.
Colour, and what it says by category
The most reliable single indicator for the categories where it applies. A green tea drifts from vivid green through olive to a dull khaki-brown, in the dry leaf and in the liquor, as its chlorophyll converts to the related olive-brown compound. Matcha shows it fastest and most obviously, which is why it is the one tea whose condition can be judged by eye before brewing. A lightly oxidised oolong dulls and yellows. A white tea darkens from silvery-green towards brown and, in the ageing formats, further towards a deep russet, which is the intended direction rather than a fault. Black tea shows very little, and heavily roasted teas and dark teas show almost nothing, which is exactly why colour cannot be used as a general test. Two cautions. Colour must be read against the tea’s own starting point rather than an ideal, since a later-picked or less thoroughly shaded leaf is duller when new. And judging colour in a liquor requires a freshly poured cup, since a standing liquor darkens on its own within the hour and reports the age of the pour rather than of the tea.
Smell, cold and then warm
The single most informative check and the least performed. Smell the dry leaf cold, then warm a small quantity in a preheated empty vessel and smell it again. Fresh leaf gives a great deal more under gentle warmth; leaf whose aromatics have gone gives very little regardless. Beyond intensity, the character of what remains places the tea in the sequence. A recent tea smells of its own specific top notes — marine and cut grass for a steamed green, chestnut and toasted bean for a pan-fired one, orchid and cocoa for a good Keemun. A middle-aged tea smells generically of tea, having lost the specific and kept the common. An old one has acquired something: a faint cardboard, old paper, hay-in-the-unpleasant-sense or slightly waxy note, which is the lipid oxidation arriving and is the marker of the later stage. If the leaf smells sour, damp or cellar-like instead, the sequence does not apply — that is a moisture failure rather than a stage of ageing, it can happen at any age, and it is a different question entirely.
Sound, feel and what they report
Well-dried tea is light, brittle and audible. Whole leaf rattles against a tin; a twisted needle snaps; a rolled pellet is hard; a pinch crushed between finger and thumb goes to powder. Leaf that has taken up moisture feels softer and faintly cool, sounds dull, bends before breaking and crushes into flakes. This test does not measure age at all — it measures moisture, which is a separate axis — and that is precisely why it belongs here. A tea that fails it has a storage problem that will have accelerated everything else, so a soft leaf and a faded aroma together mean something different from a faded aroma alone. In compressed teas the equivalent check is how the cake behaves under a pick: a well-kept cake parts into flakes along its layers, and one that has taken up moisture feels softer and gives crumbs. Neither observation is conclusive on its own. Taken together with colour and smell they usually settle whether a tea is simply old, has been badly kept, or is both — which is the distinction that decides whether the tea is worth brewing carefully or worth brewing at all.
What the cup adds
Brew it and take three readings. The wet leaf after the first infusion is the richest aromatic signal available and it separates a faded tea from an intact one immediately, because a fresh tea’s wet leaf is loud regardless of how the liquor tastes. The balance in the cup places the stage: an aged tea reads flat and one-dimensional with the astringency proportionally more exposed, because the sweetness that balanced it has gone before the grip has. And the behaviour across infusions is decisive, since a tea near the end of the sequence is exhausted quickly and gives progressively less of the same thin thing, while an intact tea keeps asserting itself and may change shape as it goes. One further test settles most remaining doubt where the household owns a second tea from the same category: brew the unknown beside a known-good example at identical parameters. That converts a judgement about an absolute into a judgement about a difference, which is what palates are actually reliable at, and ten minutes of comparison resolves a question that an hour of solitary attention leaves open.
The categories where this does not work
Ageing teas, comprehensively. A sheng cake, a pressed white and a traditionally roasted oolong all darken, soften and change aromatically with time as a matter of design, and warm storage produces in months a colour that looks like years — which is why an age claim on a dark tea is unverifiable in principle and why colour is the single worst guide there. The same applies to shou pu-erh and hei cha, which start dark. Heavily flavoured teas are a second exception, since the flavouring both dominates and disperses on its own schedule and tells you about the addition rather than the leaf. Blends with visible botanicals are a third, since the components age separately. And smoked teas are close to unreadable by smell for obvious reasons. Where the method does not apply, the honest answer is that the household cannot date the tea, and the practical response is the same one this catalogue gives for every unverifiable claim: judge the cup, buy small first, and prefer sellers who state what they know. Dating by leaf is a useful skill on half the catalogue and it is not a substitute for a harvest date on any of it.