Packaging
Closure selection
Choosing between cork, crown, screwcap, cage and swing-top, a decision that fixes how much oxygen reaches the cider, whether it can hold pressure, and which faults it is exposed to.
Also called stoppering, corking, capping.
- Stage
- Packaging
- Traditional in
- No single tradition — used wherever it suits
- What it most changes
- Oxidative character and Carbonation
- Safety
- None recorded
What it is
The closure is the only part of a glass package that is not inert, and choosing one commits the cider to a particular ageing path. The realistic options are natural cork, technical and agglomerate corks built from granulated cork and binder, the champagne cork with wire cage, the crown cap in its various liner formulations, screwcaps with different liner constructions, and the swing-top with its replaceable gasket. Each differs in how much oxygen it lets past, how much pressure it will hold, whether it can carry a taint of its own, and how it behaves over years rather than months.
Why it is used
- It determines the oxygen transmission rate of the finished package, and therefore how fast the cider oxidises after it leaves the producer — the single largest influence on its ageing trajectory.
- It sets the pressure the package can hold, which decides whether bottle conditioning, traditional-method sparkling cider or forced carbonation are available options at all.
- It carries a large part of the product’s presentation, since a champagne cork, a crown and a screwcap communicate three different things to a buyer before the bottle is opened.
How it works
- Every closure has a measurable oxygen transmission rate. Natural cork varies widely piece to piece, technical corks are more consistent but not zero, crown caps depend heavily on the liner compound, and a tin-lined screwcap approaches a near-total seal.
- Pressure retention depends on the mechanical grip: a champagne cork held by a wire cage and a properly applied crown will both hold substantial pressure, a still-wine cork will not, and a swing-top holds pressure only as long as its gasket is sound and correctly seated.
- Cork taint arises when filamentous fungi methylate chlorophenol precursors present in cork and in the wider cellar environment, producing 2,4,6-trichloroanisole; this is detectable at extremely low concentrations, masks fruit aroma before it becomes recognisable as a mustiness of its own, and is a property of the individual closure rather than the batch.
- Under a closure with very low ingress the cider receives essentially no oxygen at all, so any sulphur compounds it carries are not oxidised away; reduction develops instead, giving struck, rubbery or sulphidic notes in a bottle that is otherwise fully preserved.
- Closures also fail slowly rather than suddenly: a crown liner that has aged, a cork that has dried in low humidity, or a gasket that has been reused too often will each begin passing gas long before anything looks wrong.
What it changes
The direction this step pushes the finished drink in, dimension by dimension. A direction, not a measurement: how far it moves depends on the juice, the temperature and how the step is carried out.
| Dimension | Direction | Why |
|---|---|---|
| Oxidative character | Either way | The closure sets the rate at which oxygen enters over years, so the same cider under natural cork and under a tin-lined screwcap will diverge steadily — one developing aldehydic, nutty character, the other holding almost exactly where it was filled. |
| Carbonation | Either way | Gas escapes through and past a closure at a rate specific to its construction, which is why a bottle-conditioned cider closed with an unsuitable stopper reads under-carbonated long before its stated life is over. |
The chemistry and the organisms
What is actually being changed, and by what. Each entry says what that compound or organism does in cider generally; this page is one place it does it.
Compounds involved
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.
Carbon dioxide
The other product of fermentation, which protects a cider from air while it is being made and, dissolved in the finished drink, changes both its texture and its perceived acidity.
Hydrogen sulphide
The rotten-egg gas a nitrogen-starved yeast produces, detectable at concentrations too small to measure easily, and removable only if it is caught before it becomes something worse.
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.
What it is done with
Crown caps, swing tops and the tools that fit them
The crown cap is a crimped steel cap with a compressible liner, the cheapest reliable pressure closure ever devised; the swing top is a reusable stopper held by a wire bail, convenient and dependent entirely on the condition of its gasket.
Corks, agrafes and muselets
A sparkling closure is a cork compressed to a fraction of its diameter and driven into the neck, held there by a metal clip during conditioning or by a wire muselet once finished — because the pressure inside would otherwise push it out.
Bottles and pressure: what glass will and will not hold
Sparkling-wine bottles are engineered and tested to hold several atmospheres; still-wine bottles are not engineered to hold any, and filling one with a carbonating cider is the most dangerous ordinary mistake in home cider making.
What can go wrong
Faults that begin at this step, or that this step makes more likely. Each one is set out with its causes and whether it can be put right.
Cork taint
A damp-cardboard, wet-newspaper mustiness from trichloroanisole, usually carried by a natural cork but capable of reaching cider by other routes.
Oxidation
The cumulative effect of oxygen on finished cider: fruit aroma flattens, colour deepens towards amber, and a bruised-apple or sherry-like character replaces the fresh one.
Reduction
A closed, stale, slightly sulphurous character in cider held under strongly oxygen-free conditions, sometimes clearing with air and sometimes not.
Under-carbonation
A cider intended to sparkle that has little or no dissolved gas, usually because the bottle conditioning never started or the closure did not hold.
Bottle over-carbonation
More dissolved carbon dioxide in the bottle than intended or than the glass is rated for — a presentation problem at the mild end and a physical hazard at the severe one.
Light strike
A skunky, cooked-cabbage or drain-like aroma produced when light acting on riboflavin generates sulphur compounds in a bottle.
Plastic and packaging taint
Plastic, rubber, adhesive or chemical notes picked up from unsuitable containers, liners, hoses, gaskets or cleaning residues.
Styles it produces
Categories in which this step is characteristic or required. Some name it in their definition; for others it is simply how they have always been made.
Bottle-conditioned cider
Cider that completes a fermentation inside its sealed bottle, generating its own carbonation and, in most cases, leaving a yeast deposit behind.
Sparkling cider
Cider carrying enough dissolved carbon dioxide to produce a persistent bubble, by bottle fermentation, tank fermentation or injection.
Sidra natural
The still, dry, unfiltered cider of Asturias and the Basque Country, wild-fermented from local high-acid fruit and poured from a height to raise a momentary sparkle.
Cidre de Normandie
Protected Normandy cider made from the region’s bitter and bittersweet fruit, characteristically low in alcohol, sweet-edged and lightly sparkling.
Pétillant cider
Lightly carbonated cider in which the gas is felt as a prickle rather than a stream of bubbles, the level most traditional bottle fermentation reaches on its own.
More on closure selection
The trade-off at the centre of the decision is that there is no closure which is right for every cider. A very low ingress closure gives control and consistency, eliminates cork taint entirely and holds aroma where the maker left it — and for a fresh, aromatic cider intended to be drunk young that is the correct answer. For a tannic, structured cider intended to develop over years, the same closure can hold the cider in a reduced, closed state indefinitely, because the slow oxygen ingress that a cork provides is doing chemical work rather than merely leaking. Bottle variation is the price of that work: natural cork varies enough that bottles from one batch age at measurably different rates, which is a defect in a consistency argument and part of the appeal in a cellaring one.
Traditions have settled on different answers and the reasons are usually structural. Normandy cidre bouché takes its name from its stopper: a champagne cork and cage, because the cider is filled with residual sugar and finishes its fermentation in the bottle under real pressure. Asturian sidra natural is typically closed with a crown, being still and intended for prompt consumption, and the traditional pour has nothing to do with the closure. German swing-top bottles persist for Apfelwein partly because they are refillable and reclosable, which suits a product sold locally in volume. English bottled cider spans the whole range, and modern producers everywhere increasingly split their own range, corking the age-worthy bottlings and crowning or screwcapping the rest.
Faults attributable to the closure are worth separating from faults attributable to the cider. A single tainted bottle in an otherwise sound case points at cork, not at the cellar; a whole batch that is oxidised points at the fill or at a liner specification, not at individual closures. Reduction is the one most often misdiagnosed, because a bottle that has been sealed too tightly for its own sulphur chemistry smells wrong on opening yet frequently opens up in the glass within minutes, which is diagnostic in itself. Practical precautions are dull but effective: buy closures to a specification rather than by appearance, store corked bottles at humidity that keeps the cork resilient, and never re-use a gasket or a cork that has already done a term of service.
Related processes
Steps that sit alongside this one, replace it, or depend on it having been done.
Packaging
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.
Packaging
Bottle pressure management
Matching the pressure a carbonated cider will actually generate to glass that can contain it, taking account of temperature and of any fermentable sugar left in the bottle.
Maturation
Bottle maturation
What happens to a cider after it is sealed in glass — which for most ciders is slow decline rather than improvement, and saying so is more useful than implying otherwise.
Carbonation
Bottle conditioning
Carbonating cider by letting a second fermentation finish inside the sealed bottle, so the gas is generated where it is going to stay.
Carbonation
Traditional method
A second fermentation in the bottle the cider will be sold in, followed by riddling the deposit into the neck and expelling it, so the drink is both bottle-fermented and clear.
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 get better with age — Some does. Tannic, dry, bottle-conditioned ciders and ice ciders can gain for several years. Light, fruit-driven and commercially filtered ciders lose their aroma and do not gain anything in exchange.
- How is sparkling cider made
- How much pressure builds up in a bottle of cider — Enough to matter. Every gram of sugar fermented in a sealed bottle produces gas, and a bottle not rated for it can fail. The French cider appellations require a minimum of 1.0 to 1.5 bar at 20 °C, and a bottle-conditioned cider can go well beyond that if it was filled with more sugar than intended.
- 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.
- Why did my cider bottles explode — Because fermentable sugar was still present, or too much priming sugar was used, and the pressure exceeded what the bottle could hold. Never bottle a cider whose gravity is still falling, and never use bottles not designed for pressure.
- Which bottles are safe for sparkling cider — A bottle intended for sparkling wine is a different object from a still-wine bottle. It is heavier, thicker, has a deep punt to distribute stress, a reinforced neck and finish designed for a crown cap or a mushroom cork, and it is manufactured and tested against a design pressure.
Where to go next
- How cider is made — The whole sequence, stage by stage, with the choices open at each one.
- Cider science — The chemistry and microbiology the methods on this page rest on.
- Troubleshooting — What goes wrong, how to recognise it, and whether it can be reversed.
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.
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.
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.