Maturation
Tank maturation
Resting cider in stainless steel or a lined vessel, where the point of the container is that it contributes nothing and admits almost no oxygen.
Also called Stainless maturation, Bulk storage.
- Stage
- Maturation
- Traditional in
- No single tradition — used wherever it suits
- What it most changes
- Oxidative character down
- Safety
- None recorded
What it is
Tank maturation is the resting of finished or nearly finished cider in an inert vessel — stainless steel, or a lined or coated tank — between the end of fermentation and packaging. Nothing is being extracted and nothing is being added; the cider is settling, degassing or holding gas, integrating, and waiting. The vessel is chosen precisely for what it does not do. It contributes no flavour, it can be cleaned and sanitised to a standard wood cannot approach, it can be sealed and held under gas, and in a tall tank of any size the liquid’s own thermal mass keeps its temperature stable.
Why it is used
- A near-anaerobic vessel preserves the volatile fruit esters and the fresh acidity that oxygen would degrade, which is the whole point for a cider whose selling proposition is fruit character.
- Stainless can be sterilised and carries no resident microflora, so a producer who has controlled the ferment does not lose that control during months of storage.
- Large volumes buffer against temperature swings, so a batch in bulk is far less exposed to a cold snap or a warm spell than the same volume split across small containers.
- A sealed tank fitted for gas allows headspace to be blanketed and the cider to be moved and packaged without air contact.
How it works
- Steel is effectively impermeable to oxygen, so the only ingress is at the headspace, at fittings and during transfer — which makes oxygen pickup a matter of operational discipline rather than of the vessel itself.
- Displacing headspace air with carbon dioxide, nitrogen or argon leaves the liquid surface in contact with a gas that neither oxidises the cider nor supports acetic acid bacteria and film yeasts.
- Thermal inertia scales with volume while heat exchange scales with surface area, so a large tank changes temperature much more slowly than a small vessel in the same room.
- Held cold and undisturbed, remaining yeast, protein and colloidal material continue to settle, so the tank also functions as a slow gravity clarifier.
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 |
|---|---|---|
| Fruit character | Preserves | Excluding oxygen leaves the volatile acetate and ethyl esters intact rather than letting them be lost to oxidative degradation over months of storage. |
| Oxidative character | Lowers | With no permeable surface and a blanketed headspace, the acetaldehyde and phenolic oxidation products that accumulate in wood simply do not form. |
| Freshness | Preserves | Stable temperature and near-anaerobic conditions hold both the aromatic profile and the acid balance close to where they were at the end of fermentation. |
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.
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.
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.
Ethyl hexanoate
One of the most powerfully aromatic esters in cider, perceptible at a few micrograms per litre, contributing green apple and aniseed to the fruit complex.
Organisms involved
Saccharomyces cerevisiae
The yeast that finishes essentially every cider, whether it arrives in a sachet or from the fruit, the press and the vessel.
Film yeasts
A functional grouping rather than a taxon: the oxidative yeasts that form a skin on cider exposed to air and consume its alcohol and acid.
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 it is done with
Stainless steel tanks
Stainless steel is inert, effectively impermeable to oxygen, and the only common vessel material that can genuinely be cleaned and sanitised — which is why it displaced wood almost completely in commercial cider making.
The floating lid and the variable-capacity tank
A floating lid is a disc that rests on the surface of the cider and seals against the tank wall with an inflatable gasket or a liquid-filled channel, so a part-full vessel carries no headspace at all — which is the only problem the design exists to solve, and a large one.
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.
Reduction
A closed, stale, slightly sulphurous character in cider held under strongly oxygen-free conditions, sometimes clearing with air and sometimes not.
Hydrogen sulphide
A rotten-egg or drain smell from hydrogen sulphide produced by stressed yeast, usually the first visible consequence of a nitrogen-short juice.
Film yeast growth
A pale, powdery or wrinkled film of aerobic yeast growing on the surface of a standing cider, consuming alcohol and acid and producing acetaldehyde.
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.
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.
Acrolein bitterness
An intense, lingering bitterness quite unlike tannin, produced when lactic acid bacteria convert glycerol to acrolein and the acrolein reacts with the cider’s phenolics.
Ropiness
Cider that pours thick and pulls into an oily thread, caused by lactic acid bacteria secreting long-chain glucan polymers into the drink.
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.
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.
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.
Still cider
Cider with no perceptible dissolved carbon dioxide, presented as a fermented fruit drink whose texture rests on body, acid and tannin alone.
Single-varietal cider
Cider made wholly or overwhelmingly from one apple cultivar, presented so that the fruit’s own character is the subject of the drink.
Dry cider
Cider fermented out or finished so that little fermentable sugar remains, leaving acid, tannin and alcohol to carry the palate.
Apfelwein
The dry, sharp, still apple wine of Hesse, fermented out from culinary and local fruit and served in ridged glasses from a stoneware jug.
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.
Still perry
Perry without carbonation, in which the fruit’s sorbitol sweetness and its texture carry a drink that has no bubble to lean on.
Apple wine
A fermented apple drink made to wine strength, usually by raising the starting gravity, and presented and taxed as a wine rather than as a cider.
Viez
The cider of the Moselle and Saarland, dry and still in the local manner, drunk from a distinctive lidded pot and named from a word for the second pressing.
Galician cider
Cider from Galicia and the north-western Iberian fringe, made in a smaller and less codified tradition than its Asturian and Basque neighbours, from a distinct local fruit population.
More on tank maturation
A stainless tank is a negative choice, and that is its virtue. Wood, however neutral, is doing things: admitting oxygen, holding organisms, taking up and releasing liquid with temperature. Steel does none of them. A cider put into a sealed tank in December and drawn off in June is very close to the cider that went in, minus what settled out. For a producer whose material is aromatic dessert or culinary fruit, or a single variety whose whole interest is its own aroma, that is exactly what is wanted, because everything wood contributes would be contributed at the expense of the fruit. The corollary is that tank maturation cannot fix anything. A cider with hard, green tannins will still have them; wood would at least have polymerised some of them away.
The practical work is all in the headspace and the fittings. A part-full tank is worse than a part-full cask in one respect: the surface area of liquid exposed to a large volume of air is considerable, and steel offers no compensating advantage. So a tank is either filled, or its headspace is displaced with inert gas and the seal actually checked, or the cider is moved into a smaller vessel. Gas blanketing is the usual answer at any scale above the very small, and carbon dioxide, nitrogen and mixtures of the two are all in use — the choice matters because carbon dioxide dissolves into the cider and nitrogen essentially does not, which has consequences for a still product. Sampling valves, level sightglasses and manway gaskets are where oxygen and spoilage organisms actually get in.
The characteristic failure is the opposite of the one wood produces. Where a cask risks acetification, a sealed tank risks reduction: a cider held long, cold and completely anaerobic on any remaining yeast can go closed and sulphurous, and because nothing is entering the vessel there is no mechanism for it to correct itself. A splash transfer that deliberately picks up a little oxygen is the usual remedy, which is an odd thing to have to do in a vessel bought for keeping oxygen out. Practice around this varies more by scale than by nation: large producers in every tradition mature in tank because it is what large-volume, consistent, fresh-tasting cider requires, while makers in Asturias, Normandy and the West Country working within traditional forms use tank alongside wood rather than instead of it.
Related processes
Steps that sit alongside this one, replace it, or depend on it having been done.
Maturation
Barrel ageing
Holding cider in wood — which may mean an old neutral vat used simply as a vessel, or fresh or spirit-seasoned oak used as a source of flavour, and the two are not the same operation.
Maturation
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.
Maturation
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.
Maturation
Cold maturation
Holding cider at low temperature so that it settles bright, sheds colloidal material and stops changing microbially, without any additive or treatment being applied.
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.
Storage
Cellar storage
Holding packaged cider in conditions that let it change slowly and predictably, where stability of temperature matters more than the temperature itself.
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 should i store cider — Cool, dark and at a steady temperature. Light causes light-strike in clear glass, warmth accelerates oxidation, and temperature swings push cider past the closure of a bottle that is not tightly sealed.
- 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.
- 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.
- What should i know about stainless steel fermentation tanks — A stainless tank is a welded vessel, usually cylindrical, in an austenitic stainless grade chosen for corrosion resistance in acidic, chloride-containing conditions. It contributes nothing to the cider and lets no oxygen in.
- How do i get rid of the sulphur smell in my cider — Racking with a little splashing usually blows off free hydrogen sulphide while it is still fresh. Once it has reacted into mercaptans the smell becomes rubbery and no longer responds to aeration.
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.
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.