Sensory descriptor
Solvent
A general chemical, thinner-like impression from ethyl acetate and higher alcohols together.
Also called Chemical, Paint thinner.
- Aroma family
- Fermentation-derived
- Does it indicate a fault?
- It depends on the style it is met in
What causes it
Where nail varnish is specifically ethyl acetate, solvent is the broader impression created when ethyl acetate combines with elevated higher alcohols — isoamyl alcohol, isobutanol, propanol and 2-phenylethanol. Higher alcohol production rises with fermentation temperature, with must turbidity, and with nitrogen conditions that force yeast to catabolise amino acids through the Ehrlich pathway. A hot, dirty, nitrogen-poor ferment therefore produces both components at once, which is why the two descriptors so often travel together.
Higher alcohols below roughly 300 mg/L in total contribute warmth and complexity; above it they read as harsh and solvent-like, and the effect compounds with ethyl acetate rather than adding to it linearly.
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.
Higher alcohols
The group of larger alcohols yeast makes from amino acids, welcome as background complexity in trace and harsh and solvent-like in quantity.
Isoamyl alcohol
The most abundant fusel alcohol in cider, made from leucine, and the direct precursor of the banana ester that defines warm-fermented styles.
Yeast-assimilable nitrogen
The nitrogen a yeast can actually use, which apple juice is chronically short of — the shortage behind both stuck fermentations and rotten-egg aromas, and the shortage keeving deliberately makes worse.
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.
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.
Saccharomyces cerevisiae
The yeast that finishes essentially every cider, whether it arrives in a sachet or from the fruit, the press and the vessel.
What raises it
Processes that increase this character, or preserve it where it would otherwise be lost.
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.
Juice settling
Letting freshly pressed juice stand cold and undisturbed so that gross solids fall, then racking the cleaner juice off the deposit before pitching.
Yeast nutrition
What a fermenting yeast population actually needs from apple juice — assimilable nitrogen, vitamins and membrane lipids — and what goes wrong when the juice cannot supply it.
Nutrient addition
Supplementing a characteristically nitrogen-poor juice so that yeast can complete fermentation without producing sulphide or stalling.
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.
About Solvent
Solvent is the descriptor for a fermentation that ran too warm on a poorly settled, poorly fed must, which is a specific and correctable set of conditions. Its appearance points at three levers: temperature, juice clarity before pitching, and nitrogen.
It should be distinguished from fusel, which is higher alcohols alone and reads as hot and heavy rather than as chemical, and from nail varnish, which is ethyl acetate alone and reads as sharp and lifted.
Others in the fermentation-derived family
Solvent, nail varnish, bread, yeast, cider-shop.
Nail varnish
The sharp solvent lift of ethyl acetate above threshold, the commonest volatile fault-adjacent note in cider.
Bread dough
A raw, yeasty, faintly sour note from live yeast in suspension, characteristic of unfiltered and bottle-conditioned cider.
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.
- 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.
- Which yeast ferments cider — Saccharomyces cerevisiae finishes almost every cider fermentation, whether it was pitched or arrived from the press house. In a spontaneous ferment it is not the first organism present, only the one that survives the alcohol it makes.
- What is yan and why does cider juice run short of it — Yeast assimilable nitrogen is the nitrogen yeast can actually use. Apple juice is usually short of it — in one Virginia survey of 108 samples, 94 per cent fell below the level wine practice treats as a minimum — which is why cider ferments stall more readily than wine ferments.
- Why does my cider smell of nail varnish or solvent — Almost always ethyl acetate, the ester of acetic acid and ethanol. It is made by stressed yeast and by acetic acid bacteria, and it is perceptible at a small fraction of the concentration the acid itself needs, so it usually announces a problem before the vinegar does.
- What is yeast nutrition in cider making
- Why add yeast nutrient to cider — Apple juice is naturally low in the nitrogen yeast needs, and a short supply causes sluggish ferments and sulphury smells. Nutrient is added to make up the shortfall — though a maker keeving deliberately wants that shortfall to remain.
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.
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 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.
Hochschule Geisenheim University — beverage technology
Hochschule Geisenheim · university · retrieved 2026-08-24
German beverage-technology research covering apple wine and fruit juice processing, including the enzymology of clarification.