Sensory descriptor
Crab apple
A small-fruit character combining very high acidity, hard green aldehydes and a marked phenolic grip.
Also called Wilding, Hedgerow apple.
- Aroma family
- Fresh apple
- Does it indicate a fault?
- No — a normal part of cider and perry aroma
What causes it
Crab apples and uncultivated wildings carry a different balance from orchard fruit: substantially higher malic acid, a higher ratio of skin and core to flesh because the fruit is small, and correspondingly high procyanidin and hydroxycinnamic acid levels. The aroma is therefore the cut-apple aldehyde set stripped of the ripe-fruit esters that a cultivated dessert or bittersweet apple accumulates, sitting over a phenolic base. It is a composite perception rather than a single molecule: acid, greenness and grip arriving together in a way orchard fruit rarely produces.
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.
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.
Procyanidins
The condensed tannins of cider fruit, whose chain length — not their quantity — decides whether the mouth registers bitterness or astringency.
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.
Hydroxycinnamic acids
The family of small phenolic acids that browns a juice, and whose release from their esters supplies the raw material for every volatile phenol a cider can develop.
What raises it
Processes that increase this character, or preserve it where it would otherwise be lost.
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.
Acid balancing
Bringing a cider to the sharpness it needs, which requires separating perceived sharpness from titratable acidity from pH — three related things that do not move together.
Tannin balancing
Setting the phenolic structure of a blend, which means handling bitterness and astringency separately because they are different perceptions produced by different sizes of the same molecules.
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 Crab apple
Crab and wilding fruit has a long history in British and Irish cider as a hedgerow addition to a blend, used for the acid and tannin that a sweet-cultivar orchard could not supply. The descriptor is met most often in small-scale and foraged production and in ciders that state a wilding component explicitly.
It is distinct from green apple, which is a note about ripeness, and from crab-apple-derived astringency, which is a structural dimension rather than an aroma. Where a cider reads as crab apple, all three usually arrive together, and the descriptor is a shorthand for the combination.
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.
Green apple
A harder, sharper apple note than fresh-cut apple, driven by (E)-2-hexenal and reinforced by high malic acid.
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.
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.
- How do i balance acid and tannin in a blend — Acid and tannin do different jobs and cannot substitute for each other: acid gives freshness and microbiological safety, tannin gives structure and length. A blend short of acid tastes flabby however tannic it is.
- What are procyanidins in cider — They are the condensed tannins of apples: chains of catechin-type units whose length decides how much of the phenolic load reads as bitterness and how much as astringency. Two ciders with identical total tannin can taste nothing alike.
- What is scrumpy — Scrumpy is an informal West Country word for strong, still, usually cloudy farmhouse cider. It has no legal definition, so it describes a style expectation rather than a guaranteed method.
- What is juice blending
- What is welsh cider
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.
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.
Marcher Apple Network · specialist organisation · retrieved 2026-08-24
Has rediscovered and DNA-fingerprinted a number of lost Welsh border cultivars. Cited for identity work on cultivars the national collections do not hold.
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.