Carbonation
Forced carbonation
Dissolving carbon dioxide into cider under pressure to a chosen level, giving complete control of the sparkle and none of the flavour a second fermentation would contribute.
Also called Injected carbonation, Carbonation by dissolution, In-line carbonation.
- Stage
- Carbonation
- Traditional in
- No single tradition — used wherever it suits
- What it most changes
- Carbonation up, acidity up
- Safety
- None recorded
What it is
Forced carbonation dissolves gaseous carbon dioxide directly into finished cider, rather than generating it inside the container by fermentation. The gas is introduced either into a sealed tank held under pressure, usually through a sintered stone or a sparging ring near the base, or into the flowing product on its way to the filler, through a Venturi or a membrane contactor. In both cases the level reached is a matter of setting a pressure and a temperature and holding them, and the cider is then transferred and filled under counter-pressure so the gas stays where it was put.
Described in full
- Layout
- Four rows, one per method, each broken into three steps read left to right. The steps are what distinguishes the methods; the finished gas level can be identical.
- Bottle conditioning
- A measured sugar addition, then sealing, then a warm rest while the remaining yeast ferments it. The gas has nowhere to go but into solution. Yeast sediment stays in the bottle, so the cider is cloudy if poured carelessly.
- Tank conditioning
- The same refermentation done in a sealed pressure tank rather than in each bottle. The tank holds the gas, the cider can then be filtered clear, and it is filled into bottles under counter-pressure so nothing is lost.
- Traditional method
- Bottle conditioning followed by riddling and disgorging: the sediment is worked into the neck, the neck frozen, and the plug of ice expelled. The result is bottle-fermented and brilliantly clear, at the cost of a great deal of handling.
- Forced carbonation
- No fermentation at all. The cider is chilled, carbon dioxide is injected until it dissolves to the target, and it is filled under pressure. Fast, exactly repeatable, and the only method that lets gas level be chosen independently of everything else.
- What differs in the glass
- Conditioned ciders carry finer, more persistent bubbles and a trace of yeast character; forced carbonation gives a coarser bead that dissipates faster. The difference is real but smaller than the difference between two ciders.
- The sediment question
- Only bottle conditioning leaves sediment in the bottle as a matter of course. Whether that counts as a flaw or as evidence of method depends entirely on the tradition being judged against.
Why it is used
- It sets the carbonation level exactly and repeatably, which a second fermentation cannot do, so every pack in a run carries the same sparkle.
- It is fast: a cider can be carbonated and filled in a day, where any conditioning route needs weeks and a warm store.
- It leaves no sediment, no additional alcohol and no residual sugar consumption, so the cider that goes into the package is the cider the blender signed off.
- It is the only practical route for keg and can formats produced at volume, and for carbonating a cider that has already been sterile-filtered.
How it works
- Henry’s law governs the equilibrium: at a given temperature, the mass of carbon dioxide dissolved in the cider is proportional to the partial pressure of that gas above it. Hold a headspace pressure long enough and the liquid arrives at the corresponding dissolved level.
- Solubility falls as temperature rises, and steeply. The same headspace pressure gives markedly more dissolved gas in a cold cider than in a warm one, which is why tank carbonation is done cold and why a warm bottle foams when opened.
- The rate at which equilibrium is reached depends on interfacial area. A sintered stone breaks the gas into fine bubbles with a very large surface, and an in-line contactor does the same in a flowing stream, so both dissolve gas far faster than simply pressurising a headspace.
- Once dissolved, the gas will leave again wherever pressure drops. Every transfer, valve and filling operation downstream must be counter-pressured, or the cider arrives in the pack under-carbonated and foaming.
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 |
|---|---|---|
| Carbonation | Raises | Gas is dissolved deliberately to a level set by the equilibrium between headspace pressure and temperature, so the dimension is being adjusted directly rather than as a by-product. |
| Acidity | Raises | Dissolved carbon dioxide forms carbonic acid and stimulates the trigeminal nerve, so a carbonated cider reads as sharper than the same cider still, without any change in titratable acid. |
| Fermentation character | Preserves | No yeast acts on the cider, so none of the bready, autolytic character of a conditioned cider develops — what was blended is what is packaged. |
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
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.
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.
What it is done with
Carbonation stones and in-line carbonation
Forced carbonation dissolves carbon dioxide into cider under pressure, either by feeding it through a sintered stone in a chilled pressure-rated tank until the cider approaches equilibrium, or by metering it into a moving stream on the way to the filler.
Counter-pressure filling
Carbon dioxide stays dissolved only under pressure, so carbonated cider poured into an open bottle foams, loses its gas and takes on air; a counter-pressure filler removes the pressure difference by purging and pressurising the bottle first, and vents it under control at the end.
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.
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.
Flat and lifeless
A cider with nothing obviously wrong and nothing to say: aroma faded, acidity dulled, finish short — usually the cumulative result of over-processing or slow oxidation.
Gushing
Cider that erupts from the bottle on opening, either because it is over-pressurised or because something in it is nucleating the dissolved gas violently.
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.
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.
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.
Sparkling cider
Cider carrying enough dissolved carbon dioxide to produce a persistent bubble, by bottle fermentation, tank fermentation or injection.
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.
Modern mainstream cider
The industrially produced, consistent, carbonated cider that accounts for most of what is sold worldwide, generally made partly from concentrate and finished to a fixed specification.
Sweet cider
Cider in which sugar is the leading sensation, whether retained from an arrested fermentation, added after it, or produced by keeving.
Fruit cider
Cider with other fruit added as juice, purée or flavouring, a category that now accounts for a large share of the global market and spans a very wide range of practice.
Modern American cider
The dominant contemporary American category: cider from culinary and dessert apples, fermented clean, often carbonated and frequently flavoured, defined against the heritage sector rather than by any tradition.
Sparkling perry
Perry carrying a persistent bubble, a presentation that suits pear’s aromatics and residual sorbitol and has a documented history going back to the seventeenth century.
Alcohol-free cider
A cider-derived drink at or near zero alcohol, distinct from apple juice in having been fermented, and facing the same problem of what replaces the ethanol.
Australian cider
Cider from Australia, dominated by a large mainstream sector using dessert fruit and concentrate, with a smaller full-juice movement working from cool-climate orchards.
Hopped cider
Cider dry-hopped or hopped in process, borrowing aroma and bitterness from a brewing ingredient to supply what low-tannin apples cannot.
Irish cider
Cider from Ireland, dominated commercially by large-scale production from Armagh and imported fruit, with a smaller full-juice sector working from orchard-grown apples.
Low-alcohol cider
Cider at a reduced strength, reached either by removing alcohol from a finished cider or by arranging for less to be produced, with different consequences for flavour.
New Zealand cider
Cider from New Zealand, made in a country with a substantial export apple industry and a small but technically confident craft cider sector.
Graff
A hybrid of cider and beer, fermented from apple juice with malt and usually hops, originating in North American homebrewing rather than in any orchard tradition.
Polish cider
Cider from Poland, a recent sector built on Europe’s largest apple crop and on dessert and culinary fruit rather than on an inherited cider tradition.
Scottish cider
Cider from Scotland, made in a cool maritime climate from dessert, culinary and cold-tolerant fruit, in a small sector built largely within recent decades.
South African cider
Cider from South Africa, where a very large mainstream category built on Western Cape dessert fruit dominates and a small craft sector works alongside it.
More on forced carbonation
The physics is simple enough to be worth stating plainly, because most carbonation problems come from ignoring one half of it. Two variables set the dissolved level: the partial pressure of carbon dioxide above the liquid and the temperature of the liquid. Get either wrong and the answer is wrong. A tank carbonated at the right pressure but a few degrees warm will be under-carbonated; the same cider carbonated cold and then warmed before filling will foam in the filler and arrive short. And because the gas leaves solution at every pressure drop, the whole path from carbonating tank to sealed package has to be held above the equilibrium pressure. Counter-pressure filling is not an accessory to forced carbonation; it is part of it.
What forced carbonation genuinely cannot do is contribute anything to flavour. In a conditioned cider the gas is a by-product: yeast ferments a small quantity of sugar in the sealed container, and the same yeast produces esters and higher alcohols, consumes oxygen, and over time autolyses to give the bready, savoury note that long lees contact develops. Injecting gas produces none of that. The comparison is often made in terms of bubble size and persistence, and claims about a finer bead from bottle fermentation are widespread, but the more defensible difference is compositional rather than physical: a conditioned cider has been changed by yeast working in the package, and a force-carbonated one has not. Both are legitimate; they are simply not the same product arrived at by two routes.
In the United States the level of carbonation is not only a sensory matter. Federal rules distinguish products by their carbonation, and where a cider falls relative to that distinction affects how it is taxed and how it may be labelled, which has shaped the American market’s preference for particular carbonation levels in a way that has nothing to do with taste. Producers there therefore carbonate to a target set partly by the tax code. Elsewhere the pressures are commercial rather than fiscal: mainstream British, Australian and much modern North American cider is force-carbonated because the format is keg or can and the volumes make any other route impractical, while French cidre and Asturian and Basque bottled ciders are conventionally carbonated by fermentation and would not be recognised as themselves otherwise.
Related processes
Steps that sit alongside this one, replace it, or depend on it having been done.
Carbonation
Tank conditioning
Running a second fermentation in a sealed pressure tank so the gas is generated by yeast but the sediment never reaches the bottle.
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.
Packaging
Kegging
Filling cider into a sealed keg for gas dispense or into a vented cask for gravity and handpump service — two formats whose difference is not the container but whether the cider ever meets air.
Packaging
Canning
Filling cider into lined aluminium, a format that blocks light completely, seals tightly and depends entirely on an intact polymer coating between an acidic drink and the metal.
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.
Stabilisation
Sterile filtration
Membrane filtration at a rating that retains viable yeast and bacteria, which is what allows a sweet cider to be shelf-stable without heat or preservative — provided the filling that follows is aseptic.
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 is sparkling cider made
- What is oxidation in cider
- What is sweet cider in america — In the United States and Canada, sweet cider means fresh, unfermented, usually unfiltered apple juice, with no alcohol in it. In Britain the same phrase means a fermented cider with residual sugar.
- Where does the fizz in cider come from — Either from fermentation trapped in a sealed container, or from carbon dioxide dissolved into the cider under pressure before filling. The French cider appellations permit only the first, and require at least 1.0 to 1.5 bar at 20 °C depending on the name.
- Why does my cider gush out when i open it — Either the cider is over-carbonated, or it is warm, or nucleation sites such as yeast and haze are releasing the gas all at once. Chilling the bottle thoroughly before opening solves most cases that are not genuine over-carbonation.
- Why is my bottled cider flat — Either there was no viable yeast left to ferment the priming sugar, or the bottles are not sealing, or it is simply too cold and needs longer somewhere warmer. Two to three weeks at room temperature is the usual minimum.
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 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.
Hard cider tax class and labelling requirements
Alcohol and Tobacco Tax and Trade Bureau (TTB) · regulator · retrieved 2026-08-24
Opened on 2026-08-24. The address CiderHQ had registered — ttb.gov/wine/hard-cider — now returns 404; the bureau publishes its cider material at ttb.gov/cider/cider-resources, and the record has been corrected. The substantive hard cider definition is in 27 CFR §§24.10 and 24.331, which CiderHQ cites directly and has verified to the passage; this page is the regulator’s own gateway and its industry circular pointer, not the operative text.