Sensory descriptor
Nail varnish
The sharp solvent lift of ethyl acetate above threshold, the commonest volatile fault-adjacent note in cider.
Also called Nail polish remover, Solventy, Acetone-like.
- Aroma family
- Fermentation-derived
- Does it indicate a fault?
- It depends on the style it is met in
What causes it
Ethyl acetate is formed by yeast esterifying ethanol with acetyl-CoA, and it is made in every fermentation. It is also made in quantity by non-Saccharomyces yeasts in the early phase of a wild ferment — Hanseniaspora valbyensis and Kloeckera apiculata are prolific producers — and by acetic acid bacteria acting on ethanol in the presence of air. Concentrations in cider commonly range from a few tens to a few hundred milligrams per litre, and its perception threshold sits somewhere around 150 to 200 mg/L depending on what else is present. Above that it reads first as pear drop, then as solvent, then unmistakably as nail varnish.
This is the archetypal intensity-dependent descriptor in cider. Below threshold ethyl acetate lifts and integrates other aromas and its absence makes a cider seem dull. Around threshold it reads as pear drop and is unremarkable in many styles. Well above it, it is nail varnish, and it is a named fault. The turn is a matter of concentration in a single compound, not of a different compound appearing.
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.
Ethyl acetate
The most abundant ester in cider, giving lift and pear-drop at low concentration and nail varnish at high, and the earliest audible warning that acetic bacteria are at work.
Acetic acid
The vinegar acid, made by bacteria oxidising ethanol whenever air reaches a cider, and the one fault in cider that no later processing can undo.
Ethanol
The alcohol yeast makes from fruit sugar, which converts a perishable juice into a keepable drink and carries most of its aroma to the nose.
The organisms that make it
Where a specific organism is implicated rather than the fruit. Naming one answers a different question from naming a molecule: what is in the cellar, rather than what is in the glass.
Hanseniaspora valbyensis
The apiculate yeast most consistently reported as dominating the first days of a spontaneous cider fermentation, and a major contributor to its aroma.
Hanseniaspora uvarum
The apiculate yeast most often reported from grapes and widely present on apples too, whose anamorph name *Kloeckera apiculata* still appears throughout older cider literature.
Kloeckera apiculata
The anamorph name for *Hanseniaspora uvarum*, still in wide use in cider writing, and often used loosely as a collective term for all apiculate yeasts.
Acetobacter aceti
An acetic acid bacterium that oxidises ethanol to acetic acid wherever cider meets air, and the organism behind most volatile acidity in cider.
What raises it
Processes that increase this character, or preserve it where it would otherwise be lost.
Wild fermentation
Letting the microflora already present on the fruit and in the press house carry the ferment, in a succession rather than as a single organism.
Microbial succession
The ordered handover of a spontaneous ferment from apiculate yeasts to *Saccharomyces* to lactic acid bacteria, and the spoilage organisms waiting at the end of it.
Racking
Moving cider off the sediment it has thrown, which both cleans the liquid and — by taking yeast and nitrogen away with the deposit — slows what is left of the ferment.
Topping up
Refilling a maturing vessel as evaporation and racking losses lower the level, so that no significant surface of cider is ever left in contact with air.
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.
The fault it points at
Meeting this descriptor above a certain intensity is how the fault below is usually noticed first.
Fault
A solvent, nail-varnish or pear-drop aroma from ethyl acetate, the most abundant ester in cider and the one that turns from lift to fault over a narrow range.
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 Nail varnish
Ethyl acetate is the compound cider makers argue about most, because two of its three production routes are entirely normal and the third is spoilage. A wild ferment generates it early and much of it is subsequently lost or re-metabolised; a cider left in a partly empty vessel generates it continuously and does not.
The diagnostic question is whether acetic acid is rising with it. Ethyl acetate from early wild yeast activity arrives without volatile acidity; ethyl acetate from acetic acid bacteria arrives with it, and that combination is heading towards vinegar rather than sitting still.
Others in the fermentation-derived family
Solvent, nail varnish, bread, yeast, cider-shop.
Bread dough
A raw, yeasty, faintly sour note from live yeast in suspension, characteristic of unfiltered and bottle-conditioned cider.
Solvent
A general chemical, thinner-like impression from ethyl acetate and higher alcohols together.
Cider shop
The characteristic smell of a working cider house — ferment, wood, fruit and a trace of acetic lift together.
Fresh yeast
The clean, faintly sulphidic smell of an active yeast population, met in young cider and during fermentation.
Fusel
A hot, heavy, spirituous impression from elevated higher alcohols, felt as warmth as much as smelled.
Lees
A cloudy, faintly bitter, sedimentary character from yeast and fruit solids carried into the glass.
Yeast extract
A savoury, umami, meaty-broth note from yeast autolysis during extended lees contact.
Fermenting vat
The pungent, CO2-lifted smell of a ferment in full activity, met in very young cider straight from the vessel.
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.
- How does cider ferment — Yeast consumes the sugar in apple juice and produces roughly equal masses of ethanol and carbon dioxide, along with the esters and higher alcohols that give cider much of its aroma. In a wild ferment several yeast species take turns before *Saccharomyces* finishes the job.
- How many calories are in cider — Roughly 40 to 60 kcal per 100 ml for most ciders, so a UK pint falls somewhere around 200 to 250 kcal. Alcohol contributes about 7 kcal per gram and residual sugar about 4, so both strength and sweetness matter.
- What is racking in cider making — Racking is siphoning cider off the sediment it has thrown into a clean vessel, leaving the lees behind. It clarifies the cider and, in traditional practice, is also used to slow a ferment by removing yeast with the lees.
- 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.
- How much acetic acid is normal in cider — A small amount is present in every cider and contributes lift. Sound Asturian sidra natural has been measured at 0.2 to 0.3 g/L, and a clean modern cider much above about 0.7 g/L is generally showing a fault rather than a style.
- 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.
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.
Peer-reviewed literature on cider fermentation microbiology
Various journals · peer-reviewed literature · registered as competent for this subject
Covers the microbial succession of spontaneous cider fermentation, the role of non-Saccharomyces yeasts in the early stages, malolactic conversion by Oenococcus and Lactobacillus species, and the organisms behind the principal spoilage faults.
Cider and perry production technical training material
Peter Mitchell / Cider and Perry Academy · reference work · registered as competent for this subject
Searched again on 2026-08-25 and it remains the one printed source here that a bibliographic check cannot fix, because it is not a published work with an edition. It is course material issued to participants of a training programme, so there is no catalogue record to verify, no ISBN, and no lawful public copy. Its state stays `registered` for that reason rather than through inattention.