The compounds released when a leaf is broken
The smell of cut grass, snapped stems and bruised leaves is one of the best-characterised aromas in plant chemistry, and it comes from a group of six-carbon aldehydes and alcohols formed rapidly when leaf tissue is damaged and its own enzymes act on the lipids in the cell membranes. Hexanal, the hexenals and the hexenols are the compounds usually named, one of which is known widely enough as leaf alcohol to have a common name. In tea these are generated during plucking, handling, withering and rolling, and they are prominent in green tea because the kill-green step halts the enzymes before the rest of the aromatic transformation has run. This is a well-established association rather than a convention, and it explains a good deal. It is why a green tea smells of the raw material and an oolong does not; why over-handled or roughly harvested leaf can read as excessively grassy; and why the green note fades quickly in storage, since these compounds are small, volatile and among the first to go. A green tea that no longer smells green has not become another category, it has lost the fraction that made it recognisable.
Vegetal against grassy, and why the catalogue keeps both
TeaHQ carries `vegetal` and `grassy` as separate flavour families, and the distinction is worth defending because it is frequently collapsed. Grassy names the sharp, fresh, cut-lawn quality that belongs to the compounds above. Vegetal names something broader and cooked — spinach, green bean, artichoke, asparagus, steamed greens — which is characteristic of Japanese steamed teas and of some Chinese greens, and which arises partly from the same family and partly from the effect of moist heat on the leaf. A steamed sencha reads vegetal; a rough spring green tea reads grassy; and a drinker who dislikes one may be perfectly happy with the other. Both are also used pejoratively by writers who mean that a tea tastes of raw plant matter and nothing else, which is a genuine fault condition in a poorly made or over-brewed green tea and is a different claim from a descriptive use. Reading which is meant is usually possible from context: a vegetal note listed alongside sweetness and umami is descriptive, and one listed alone is a complaint.
Marine, and where it comes from
Marine is the descriptor for the seaweed, nori, ocean-adjacent quality that characterises shaded Japanese teas and deep-steamed sencha, and TeaHQ carries it as an aroma descriptor. Japanese tea vocabulary names the covered aroma of shaded leaf specifically, describing it as a deep, marine, slightly sweet fragrance quite unlike the fresh grassiness of an unshaded tea, and it is the single most reliable way to identify a shaded tea blind. On the chemistry, the group most often discussed in connection with marine and seaweed character in foods generally is the volatile sulphur compounds, dimethyl sulfide among them, and the same compounds are named in accounts of steamed green tea aroma. TeaHQ reports that association as a well-supported direction and does not assert that any single compound accounts for the character, for the same reason it declines every other single-compound explanation. What is certain is the agronomic connection: shading produces the note, the note is one of the things the practice is for, and matcha carries it in concentrated form because it is ground tencha.
The saltiness question, and why the catalogue answers it this way
Tasting notes occasionally describe a saline or briny quality in deep-steamed greens, in gyokuro and in some mineral-heavy rock teas, and Sprint 31 recorded a deliberate decision not to carry saltiness as a sensory axis. That decision stands and the reasoning is worth restating here, because this is the family where the impression arises. A genuine sodium-driven saltiness is not something the catalogue has evidence for. The more plausible readings are that the impression comes from the marine aromatics of shaded and steamed leaf, from mineral content in the water, or from an interaction with the savoury umami character. The water is worth eliminating first and is the easiest to check: mineral content varies enormously between supplies and between bottled waters, a water with a noticeable mineral character contributes it to every tea brewed with it, and anyone who finds several unrelated teas sharing a briny edge is probably describing their water. Brewing one of them with a different water settles it in ten minutes. A descriptor that is reported rarely and explained uncertainly does not earn a place in a controlled vocabulary, and marine covers the ground honestly.
How brewing moves the green family
This family is unusually responsive to preparation, which makes it a good demonstration of how much of a tasting note is a brewing decision. Water that is too hot drives the light green volatiles off in the steam before they reach the drinker and simultaneously extracts more of the polyphenol fraction, so an over-hot green tea reads as less green and more bitter at once — the opposite of what most people expect. A very cool steep selects the amino acid fraction efficiently and also releases fewer volatiles, so a technically correct low-temperature gyokuro can under-report the covered aroma the tea was made for, which is why many drinkers run a very cool first infusion and a warmer second. Long steeping shifts everything towards the astringent late fraction and buries the green character underneath it. And cold brewing produces a sweet, low-astringency liquor in which the green family reads cleaner and lighter than it does hot. Four preparations, four sets of descriptors, one leaf.
Steaming, pan-firing and the fork that sets the family
The kill-green method is the earliest decision in green tea manufacture and its aromatic consequences persist to the cup. Steaming, dominant in Japan, uses moist heat that halts the enzymes quickly and preserves the fresh green, marine and vegetal character. Pan-firing, dominant in China, applies dry heat to the leaf surface and initiates a small amount of browning chemistry, which is why Chinese green teas so often show chestnut, bean and toasted notes where Japanese ones do not. Neither is more authentic; they are two solutions to the same problem adopted in different places, and the difference is one of the largest and most reliable distinctions in the whole category. Steaming depth then modulates it further: a longer steam breaks the leaf down more and gives a cloudier, sweeter, fuller cup, and a shorter one keeps the liquor clearer and more delicate. A drinker who has decided they dislike green tea has very often tried one point on this map, and the two ends of it are further apart than many teas from different countries.