Sensory descriptor
Green apple
A harder, sharper apple note than fresh-cut apple, driven by (E)-2-hexenal and reinforced by high malic acid.
Also called Granny Smith, Hard green apple.
- Aroma family
- Fresh apple
- Does it indicate a fault?
- No — a normal part of cider and perry aroma
What causes it
The same lipoxygenase pathway that makes hexanal also makes (E)-2-hexenal, which carries a distinctly greener, leafier and more cutting character than its saturated counterpart. Where fruit is picked short of full ripeness the ratio favours the unsaturated aldehyde, and the perception moves from cut apple towards green apple. Malic acid reinforces it: acidity is processed alongside aroma, and a high-acid sharp cultivar will read greener at the same aldehyde concentration than a low-acid bittersweet one. Acetaldehyde, from mild oxidation or from a ferment stopped early, adds a third green layer that is chemically unrelated but perceptually indistinguishable to most drinkers.
The compounds responsible
Where the molecule is established. Some descriptors in this lexicon name a compound the compound register does not yet hold a record for; those are named in the cause above instead.
trans-2-Hexenal
The sharper, more penetrating green aldehyde of the same pathway as hexanal, made from linolenic rather than linoleic acid, and a marker of underripe fruit.
Malic acid
The acid of apples, which supplies almost all the sharpness a cider has and, through pH, decides how vulnerable that cider is to everything that could spoil it.
Acetaldehyde
The compound sitting one step short of ethanol, which smells of bruised apple and sherry, binds most of the sulphite added to a cider, and is the chemical signature of oxidation.
What raises it
Processes that increase this character, or preserve it where it would otherwise be lost.
Ripeness assessment
Judging when cider fruit has converted enough starch, loosened enough on the spur and hardened enough for the store to be worth gathering.
Starch–iodine testing
Staining a cut apple with iodine solution so that remaining starch turns blue-black, giving a visible map of how far conversion to sugar has progressed.
Hand harvesting
Taking fruit off the tree by hand into bags and bins, so that it arrives at the store undamaged and with its stalk intact.
Juice blending
Combining juices from different cultivars before fermentation so that the blend ferments as a single batch, as against fermenting separately and blending later.
Where it is usually met
Fruit and styles this character is recorded in. A record here is where the descriptor is commonly found, not a claim that every example shows it.
About Green apple
Green apple is the note that separates an early-picked sharp cider from a late-picked bittersweet one, and it is one of the more diagnostic descriptors on a judging sheet because it points at a decision made in the orchard rather than in the cellar. Eastern counties fruit and modern dessert-fruit blends carry it as a matter of course; a West Country bittersweet blend that shows it has usually been picked or pressed early.
The confusion worth naming is with acetaldehyde. A cider showing green apple from oxidation smells green and flat, with the fruit ester layer stripped out; one showing green apple from fruit chemistry smells green and lively, with esters intact. Judging the two together as a single "green" score is the commonest error made by untrained panels.
Others in the fresh apple family
Crisp, green, just-cut apple and apple skin.
Fresh-cut apple
The smell of a cut apple surface, produced within seconds of the fruit tissue being broken by six-carbon aldehydes released from membrane fats.
Apple skin
The dry, faintly waxy and slightly bitter aroma of the fruit’s surface rather than its flesh, carried by cuticular waxes, hexyl esters and skin-concentrated phenolics.
Pressed apple juice
The full, sweet, unfermented smell of fresh juice, met in cider where residual sugar and surviving fruit esters combine.
Apple pomace
The wet, sweet-sour smell of freshly milled and pressed pomace: cut-apple aldehydes over the first traces of wild fermentation and browning.
Crab apple
A small-fruit character combining very high acidity, hard green aldehydes and a marked phenolic grip.
Russet apple
A dry, nutty, faintly pear-like apple character associated with russeted skin and high soluble solids.
Unripe apple
A hard, starchy, low-aroma character from fruit milled before the climacteric, with acid high and esters not yet formed.
Apple core
A faintly bitter, faintly almond-like note from crushed pips and core tissue passing through the mill with the flesh.
What people ask next
Questions readers ask about the things this page mentions. Each one goes to the section that answers it rather than to a page written to receive the question.
- What is malic acid and why does it matter in cider — Malic acid is the acid of apples and supplies almost all the sharpness a cider has. It also sets pH, which decides how well sulphite works and how exposed the cider is to spoilage, so it does far more work than its taste suggests.
- When are cider apples harvested — In the northern hemisphere the cider harvest runs from about September to November, with late bittersweets such as Dabinett and Vilberie coming in last. Cider fruit is generally picked riper than dessert fruit, and often gathered from the ground.
- How are cider apples picked
- How do you know when cider apples are ripe — The usual field test stains a cut apple with iodine: starch turns black, so the less staining there is, the more starch has turned to sugar and the riper the fruit. Pip colour and the ease with which fruit parts from the spur are the traditional signs.
- What is juice blending
- How is supermarket cider made
Where to go next
- The sensory model — The thirteen structural dimensions and the twenty aroma families, in full.
- Compounds — The chemistry behind the words.
- Troubleshooting — When a perception turns out to be a problem, this is where it is diagnosed.
Sources
What this page rests on. Where a source is marked as registered rather than read, CiderHQ is recording that the body is authoritative on the subject without claiming to have worked through the document itself. See our evidence policy for what each state means.
Washington State University cider research programme
Washington State University Northwestern Washington Research and Extension Center · university · passage verified 2026-08-24
The single most useful open cider dataset CiderHQ has found. The programme’s cultivar performance database gives juice chemistry, orchard behaviour, bloom and harvest timing and cider-maker tasting notes for 73 cultivars grown at one maritime site over fifteen years, and — unusually — publishes its classification thresholds alongside its figures, so the classification can be checked rather than taken on trust. It also states outright that its results diverge from the English ones. Read in full on 2026-08-24 and transcribed into `data/trials/wsu-mount-vernon.ts`; four published figures were found to be impossible and are withheld there with their reasons.
The Science of Cidermaking and associated technical writing
Andrew Lea · reference work · passage verified 2026-08-24
Written by a food chemist who worked at Long Ashton on apple phenolics. Unusual among specialist cider writing in that it is primary-research-adjacent: the author is describing work he did, and cites the literature. This is why it is registered at tier 1 for chemistry while a general cider book is not.
A Somerset Pomona: The Cider Apples of Somerset
Liz Copas, The Dovecote Press, 2001. ISBN 9781874336877 · reference work · bibliographic record verified, not opened 2026-08-25
Bibliographic record verified on 2026-08-25 against Open Library: Liz Copas, The Dovecote Press, 2001, ISBN 9781874336877. The author was Long Ashton’s cider pomologist, which is why this work is registered for Somerset cultivar identity at all — it is the nearest thing to a successor to the station’s own descriptions. No copy was opened. Not digitised in any open collection.