Sensory descriptor
Unripe apple
A hard, starchy, low-aroma character from fruit milled before the climacteric, with acid high and esters not yet formed.
Also called Starchy apple, Immature fruit.
- Aroma family
- Fresh apple
- Does it indicate a fault?
- No — a normal part of cider and perry aroma
What causes it
An apple converts starch to sugar and begins ester synthesis at the climacteric, the burst of respiration triggered by its own ethylene production. Fruit milled before that point carries starch that yeast cannot ferment, malic acid at its seasonal peak, and almost none of the hexyl and butyl esters that give ripe fruit its aroma. What is left is the green aldehyde fraction over a starchy, faintly chalky base. Starch-iodine testing exists precisely to catch this: the stain pattern on a cut apple reports how far conversion has gone, and a cider pressed from understained fruit will be thin, sharp and short of fruit for its whole life.
Mild under-ripeness reads simply as a sharp, green cider. Marked under-ripeness carries enough unconverted starch through to produce a persistent haze that pectinase will not clear, at which point it is a fault with a name.
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.
Starch
The fruit’s carbohydrate store, unfermentable until ripening converts it to sugar, and the reason picking early costs alcohol and risks a haze that will not clear.
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.
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.
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.
Sweating the fruit
Deliberately heaping or storing gathered fruit so that it softens, loses water and finishes converting starch before it goes to the mill.
The fault it points at
Meeting this descriptor above a certain intensity is how the fault below is usually noticed first.
Fault
A persistent haze caused by starch carried in from under-ripe fruit, which has not yet been converted to sugar and stays suspended in the cider.
About Unripe apple
This descriptor is a diagnosis of a harvest decision, and it is the one fresh-apple note that cannot be corrected downstream. Blending can mask it, sweetening can cover it, but the esters that were never made in the fruit cannot be added back.
It is worth distinguishing from green apple. Green apple is a bright, cutting note that a cider can carry as a style; unripe apple is green with a hole where the fruit aroma should be, and panels describe it as hollow or short as often as they describe it as green.
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.
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.
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 does sweating apples mean — Sweating is holding picked fruit in a heap or store for days or weeks before milling, so it softens, loses water and gains sugar concentration. Perry pears in particular are usually held until they yield to the thumb.
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.
Cornell Cider Research and Extension programme
Cornell University, School of Integrative Plant Science · university · passage verified 2026-08-24
Runs cultivar trials in New York State and publishes juice chemistry for European cider varieties grown in a North American climate — the single most useful counterweight to treating English figures as universal.
The New Cider Maker’s Handbook: A Comprehensive Guide for Craft Producers
Claude Jolicoeur, Chelsea Green Publishing, 2013. ISBN 9781603584739 · reference work · bibliographic record verified, not opened 2026-08-25
Bibliographic record verified on 2026-08-25 against the Open Library union catalogue: Chelsea Green Publishing, 2013, ISBN 9781603584739, one edition recorded. That establishes the citation points at a real book in a stated edition, which is what a citation needs and is all it establishes. No copy was opened and nothing is quoted from it. The book itself is in print and not digitised in any open collection; where CiderHQ needs a figure from this territory it uses an accessible research source instead and says so.