Sensory descriptor
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.
Also called Cut apple, Just-cut apple.
- Aroma family
- Fresh apple
- Does it indicate a fault?
- No — a normal part of cider and perry aroma
What causes it
When apple tissue is ruptured — by a knife, by a mill, or by a bruise — lipoxygenase and hydroperoxide lyase come into contact with linoleic and linolenic acid released from the cell membranes and convert them, in seconds, into the six-carbon aldehydes hexanal and (E)-2-hexenal. These compounds do not exist in the intact fruit in any quantity; they are made by the act of cutting it. That is why a whole apple smells of very little and a cut one smells sharply of apple, and why the aroma of milled fruit in a cider house is at its most intense in the first minutes after the mill. In finished cider the note survives where fermentation was cool, sulphite protection adequate and oxygen exposure low; it is among the first things lost to time and air.
The same aldehydes at higher concentration stop reading as apple and start reading as green, grassy and hard — the note this lexicon separates as green apple. The threshold is a matter of degree rather than of a different molecule.
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.
Hexanal
The green-apple aldehyde generated within seconds of breaking fruit tissue, which gives fresh juice its cut-grass smell and is largely converted away by the yeast.
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.
Dissolved oxygen
Essential to a healthy yeast population at the start of fermentation and the principal enemy of a cider from the moment fermentation ends.
What raises it
Processes that increase this character, or preserve it where it would otherwise be lost.
Milling
Reducing whole fruit to a pulp so that the press has cell walls it can drain, rather than intact apples it can only bruise.
Fermentation temperature control
Managing the temperature at which a ferment runs, which sets not only how fast it goes but which aromatics survive it and what the finished cider tastes of.
Cold maturation
Holding cider at low temperature so that it settles bright, sheds colloidal material and stops changing microbially, without any additive or treatment being applied.
Sulphiting
Adding sulphur dioxide to juice to suppress spoilage organisms and oxidative browning, at a level that only means anything once the juice pH is known.
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 Fresh-cut apple
This is the reference point of the whole fresh-apple family and the descriptor most often used as shorthand for a cider tasting of the fruit it was made from. It is a genuinely useful term precisely because its chemistry is unambiguous: a trained panel scoring fresh-cut apple is scoring the survival of a small group of aldehydes through processing, and that in turn reports on ferment temperature, oxygen management and time in package.
It is routinely confused with two other things. One is residual sugar — a dry cider carrying strong fresh-apple aroma is frequently described as sweet, because aroma and sweetness are integrated before the drinker becomes aware of either. The other is carbonation, which sharpens the perception of both acid and volatile aroma and so makes the same liquid read fresher poured sparkling than poured flat.
Others in the fresh apple family
Crisp, green, just-cut apple and apple skin.
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.
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 temperature should cider ferment at — Most cider is fermented cool, commonly between about 12 and 18 °C. Cooler ferments keep more fruit aroma and run slower; above the low twenties the cider tends towards hot, solvent-like higher alcohols.
- How are apples milled for cider
- Why is sulphite added to cider — Sulphur dioxide suppresses spoilage bacteria and wild yeast before fermentation and protects the finished cider from oxidation. How much of it is active depends strongly on pH, which is why low-acid juice is harder to protect.
- Does carbonation change how cider tastes — Yes. Dissolved carbon dioxide forms carbonic acid, so a sparkling cider tastes sharper than the same cider still, and the bubbles carry aroma upwards and scrub fat from the palate.
- How is supermarket cider made
- Is single variety cider better than a blend — Neither is inherently better and CiderHQ does not rank them. A single varietal shows one cultivar’s character and depends entirely on that fruit being balanced; a blend is how most makers reach balance deliberately.
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.
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.
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.
Peer-reviewed literature on apple phenolics and cider sensory perception
Various journals · peer-reviewed literature · registered as competent for this subject
Registered as a class rather than as one paper, because the mechanisms CiderHQ describes — tannin chain length driving the split between bitterness and astringency, salivary protein precipitation, enzymatic browning — are established across many studies rather than resting on any single one. Individual papers are cited where a specific number is quoted.