Sensory descriptor
Struck match
The sharp, mineral, matchhead note of free sulphur dioxide above its perception threshold.
Also called Matchstick, Burnt match, Sulphite.
- Aroma family
- Sulphur
- Does it indicate a fault?
- Usually, yes
What causes it
Sulphur dioxide added as a preservative exists in equilibrium between molecular SO2, bisulphite and bound forms, and it is the molecular fraction — which rises as pH falls — that is volatile and perceptible. Above roughly 30 to 40 mg/L free SO2, and lower still in a low-pH cider, it is detectable as a sharp matchhead note that also prickles the nose. It is entirely additive in origin, unlike the other sulphur descriptors, and it is a dosing error rather than a fermentation problem.
Free SO2 below its perception threshold is invisible to a taster and is doing necessary work protecting the cider from oxidation and microbial spoilage. Above it, the note is obvious and no framework accepts it, and there is no route back other than time and oxygen.
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.
Sulphur dioxide
The antimicrobial and antioxidant on which most modern cidermaking depends, and whose effectiveness collapses as pH rises — which makes every sulphiting decision a pH decision first.
Acetaldehyde
The compound sitting one step short of ethanol, which smells of bruised apple and sherry, binds most of the sulphite added to a cider, and is the chemical signature of oxidation.
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.
What raises it
Processes that increase this character, or preserve it where it would otherwise be lost.
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.
Sulphite stabilisation
Managing free sulphur dioxide through maturation and at packaging so that a useful antimicrobial and antioxidant fraction survives into the bottle.
Bottling
Transferring finished cider into glass, where the dominant variable is how much oxygen the liquid picks up in the few seconds it takes to fill and close each bottle.
Juice storage
Holding unfermented juice sound between pressing and fermentation, by chilling, sulphiting, gas blanketing, freezing or aseptic filling.
The fault it points at
Meeting this descriptor above a certain intensity is how the fault below is usually noticed first.
Fault
A struck-match or burnt-match aroma and a prickle at the back of the nose from too much free sulphur dioxide, with a real health consideration for sulphite-sensitive people.
About Struck match
Struck match is one of the few faults that is a pure dosing question. It arises where sulphite is added by habit rather than by measurement, and where the pH-dependence of molecular SO2 has been ignored: the same addition that is barely adequate at pH 3.8 is excessive at pH 3.2.
It is worth distinguishing from reduction, with which it is constantly confused. Both are sulphurous and sharp, but reduction comes from the yeast and responds to aeration, while excess SO2 comes from the bottle and does not.
Others in the sulphur family
Rotten egg, struck match, drains, rubber, cooked cabbage.
Rotten egg
Hydrogen sulphide from yeast under nitrogen stress — the commonest sulphur fault and the most correctable.
Drains
A heavy, stagnant, sewer-like note from mercaptans formed when hydrogen sulphide is left to react.
Cooked cabbage
A vegetal sulphur note from dimethyl sulphide, rising slowly during storage rather than during fermentation.
Flinty
A sub-threshold reductive note read as struck flint rather than as sulphur, the mildest state of reduction.
Lightstruck
A skunky, sulphidic note produced when light degrades riboflavin in clear or green glass.
Rubber
A burnt-rubber note from disulphides and higher mercaptans, generally a late stage of reductive fault.
Garlic
A pungent allium note from specific thiols and disulphides, occasionally from orchard spray residues.
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.
- Does cider contain sulphites — Most does. Sulphur dioxide is added to protect juice and finished cider, and fermentation itself produces a small amount even when none is added. European labels must declare it above 10 mg per litre.
- 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.
- 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 is cider bottled
- How long can apple juice sit before i ferment it — Only hours at room temperature before wild fermentation begins. Chilled and sulphited it can be held for a day or two; beyond that it needs freezing, pasteurising or fermenting.
- What is acetaldehyde
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.
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.
European Food Safety Authority scientific opinions
EFSA · regulator · retrieved 2026-08-24
Registered for the food-safety questions cider genuinely raises: patulin in juice from rotten fruit, sulphite sensitivity, and the toxicology behind additive limits.