Compound
Pectin
The structural polysaccharide of fruit cell walls, which decides how much juice a press releases, whether a cider ever clears, and whether keeving is possible at all.
Also called Pectic substances, Protopectin.
- Class
- Polysaccharides
- Formula
- Not a single molecule — see below
- How often it matters
- Present in every cider
What it does in cider
- Cements plant cells together in the fruit, so its breakdown during ripening is what makes an apple soft and a pear buttery.
- Holds water in the pomace and raises juice viscosity, cutting press yield and slowing every subsequent settling and filtration step.
- Stabilises a colloidal haze that no amount of time will drop, because the charged, hydrated polymer keeps suspended particles apart.
- Becomes the raft of a keeve: de-esterified by pectin methylesterase and cross-linked by calcium, it forms a gel that floats to the surface and takes the juice’s nutrients with it.
- Contributes to mouthfeel in the small fraction that survives into the finished drink, adding a perceptible fullness in unfiltered ciders.
How it is perceived
What the compound registers as, and at roughly what concentration. Perception is not a property of the molecule alone: sugar, tannin and carbonation all change where a threshold falls.
- fullness
- slight viscosity
Not tasted or smelled directly. What a drinker perceives is texture and clarity: the same cider with and without pectinase treatment differs visibly in the glass and slightly in weight on the palate.
Descriptors it is responsible for
Sensory records that name Pectin as a cause. Each states the perception and the mechanism behind it.
- Lees — A cloudy, faintly bitter, sedimentary character from yeast and fruit solids carried into the glass.
- Stewed apple — Soft, wet, low-definition cooked fruit without browning, from prolonged gentle heat or long warm storage.
- Apple sauce — Cooked culinary-apple character with the sharpness retained, met where high-acid fruit has been heat-treated.
- Bletted pear — Deep, faintly winey overripe pear character from fruit softened past ripeness, met in traditional perry and in medlar-like notes.
The structure it moves
| Dimension | What it is |
|---|---|
| Body | How much weight and viscosity the drink has in the mouth. |
Measured figures
Shown as they were measured, with the context each was taken in. They are not averaged: a concentration recorded in one country's fruit in one decade is not a constant.
Pectin0.5–2.5 g/L
context not recorded · Andrew Lea
Read this as an order of magnitude, not a specification. Pectin is a family of polymers rather than one compound, reported figures depend entirely on the assay used, and most of the fruit’s pectin never leaves the pomace at all. Maceration time, milling severity and the fruit’s own enzyme activity move the juice figure more than cultivar does.
Structural polysaccharide that holds haze and enables keeving. Measured in grams per litre.
What forms it
Processes that put this compound into the drink, or increase how much of it is there.
Milling
Reducing whole fruit to a pulp so that the press has cell walls it can drain, rather than intact apples it can only bruise.
Maceration
Holding milled pomace before pressing so that phenolics, aroma precursors and pectin have time to move out of the solid tissue and into the juice.
Pomace conditioning
Letting milled pomace stand before it goes to the press so that it drains better, presses faster and gives more juice.
What removes or limits it
Processes that reduce it, hold it below a threshold, or stop it forming in the first place.
Pectinase treatment
Adding pectin-degrading enzyme preparations to juice so that haze-forming and viscosity-forming pectin is broken down before fermentation.
Enzyme addition to pomace
Dosing pectin-degrading enzyme into milled pomace rather than into juice, to raise press yield and change how the cake drains.
Keeving
Forming a floating pectin gel that lifts nutrients and solids out of the juice, so that the ferment starves before it finishes and leaves natural sweetness behind.
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.
Filtration
Passing cider through a porous medium to reach a stated visual brightness, at a real cost in colloidal material, body and aroma.
Fining
Adding a reactive agent that binds a target colloid and carries it to the bottom, chosen according to whether the problem is tannin, protein or a phenolic taste fault.
Faults it is implicated in
Being implicated is not the same as being a fault. Several of the compounds on this site are ordinary constituents of a sound cider and define a named fault only above a concentration.
Pectin haze
A persistent, slightly viscous haze that will not settle, caused by pectin from the fruit remaining in solution as a colloid.
Excessive sediment
More deposit in the bottle or vessel than the presentation intends, ranging from a normal conditioning yeast layer to a loose sludge that clouds every pour.
Thin body
A cider with no weight or texture in the mouth, most often from over-watered pomace, low-gravity juice or a blend with nothing to give it substance.
Organisms that produce it
Which organism is responsible usually decides whether the compound is a feature or a symptom.
Botrytis cinerea
Grey mould: a broad-host-range fruit rot whose laccase enzyme oxidises phenolics and whose glucans make a juice difficult to clarify.
Penicillium expansum
The blue mould of stored apples and the principal producer of patulin, the one genuine chemical safety issue that rotten cider fruit raises.
About Pectin
Pectin is the mortar of plant tissue: long chains of galacturonic acid, many of them esterified with methyl groups, interrupted by branched regions carrying neutral sugar side chains. In an unripe apple it is present as insoluble protopectin, locked into the cell wall and holding the fruit hard. Ripening solubilises it, which is why fruit softens, and milling and pressing release a portion of the soluble fraction into the juice. How much gets there depends on how hard the fruit was milled, how long the pomace sat before pressing, and how far the fruit’s own enzymes had already gone.
In the juice, pectin causes two distinct problems that are often confused. The first is mechanical: pectin makes juice viscous and holds water in the pomace, so a pectin-rich mill flows slowly through a press and gives up less juice. The second is colloidal: the dissolved polymer is charged and heavily hydrated, and it keeps fine solids in suspension indefinitely. A pectin haze does not settle, does not respond to fining and blinds a filter, and it is diagnosed not by looking at it but by mixing a sample of the cider with an equal volume of alcohol, which precipitates pectin as visible gelatinous clots. The answer, where clarity is wanted, is a pectinase preparation applied to the juice or to the pomace, which cuts the chains and dismantles the colloid.
The most interesting thing about pectin in cider is that the traditional method turns it into an asset. Keeving begins with pectin methylesterase — the fruit’s own, in the classical Norman and Herefordshire practice, or an added preparation in modern industrial keeving — stripping the methyl esters off the pectin backbone. That exposes carboxyl groups that carry a negative charge. Add calcium, which is normally present as a salt in the juice or added deliberately, and each calcium ion bridges two chains. The polymer network that forms is calcium pectate: a coherent gel rather than a precipitate.
What makes the gel useful is that it floats. A slow, cold, incipient fermentation generates just enough carbon dioxide for the bubbles to lift the gel to the surface as the chapeau brun, the brown cap, and the maker racks clear juice out from beneath it. The cap takes with it the suspended solids, much of the yeast population and, decisively, most of the assimilable nitrogen. The juice left behind is clean, nutrient-starved and ferments slowly to a natural stop with sugar still in it. This is the traditional route to a sweet cider without added sugar, without sterile filtration and without pasteurisation, and it exists because a structural polysaccharide can be persuaded to form a raft.
Related compounds
Compounds it is formed from, converted into, confused with, or routinely met alongside.
Acids
Galacturonic acid
The sugar acid that pectin chains are built from, released as they break down, and a significant part of why juice from rotten fruit binds so much of the sulphite added to it.
Enzymes
Pectin methylesterase
The enzyme that strips methyl groups from pectin, exposing the charged sites that calcium bridges — which is the reaction the whole of keeving is built on.
Enzymes
Pectin lyase
The chain-cutting activity in a commercial pectinase preparation, which raises press yield and clears a juice by destroying the colloid pectin creates — and destroys the possibility of keeving in the same stroke.
Polysaccharides
Calcium pectate
The gel formed when calcium bridges de-esterified pectin chains, which floats to the surface as the brown cap of a keeve and carries the juice’s nutrients out with it.
Alcohols
Methanol
A small alcohol released not by fermentation but by enzymes stripping methyl groups off pectin, which is why juice handling rather than yeast choice governs how much a cider contains.
Polysaccharides
Arabinan
The branched neutral sugar side chains of pectin, which can be liberated intact by pectinase treatment and then form a haze that appears weeks after the juice looked perfectly 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.
- How do i clear a cloudy cider
- Why is there sediment in the bottom of my cider bottle — In a bottle-conditioned cider the sediment is yeast and is expected — pour carefully and leave the last centimetre. In a filtered cider it means something has grown since bottling.
- Is cider vegan — Cider itself is a plant product, but some producers clarify it with animal-derived finings such as gelatine, isinglass or chitosan. Vegan status therefore depends on the fining regime, which is why some ciders are certified and others are not.
- How are apples milled for cider
- What is keeving — Keeving is a technique for starving a ferment of nitrogen so that it stops before all the sugar is gone, leaving a naturally sweet cider. Pectin is made to gel and float as a brown cap, carrying nutrients and yeast out of the juice with it.
- Is there methanol in cider — Yes, in small quantities: methanol is released when pectin in the fruit is broken down, and it is present in all fruit juices and fruit-based drinks. The concentration in cider is far below any level of concern, though it matters when cider is distilled.
Where to go next
- All compounds — Grouped by what the fruit brings and what the ferment makes of it.
- Sensory — Every descriptor, with the compound or process that causes it.
- Microbiology — The organisms whose metabolism most of this chemistry belongs to.
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.
Institut Français des Productions Cidricoles (IFPC)
IFPC · research institute · retrieved 2026-08-24
The French technical institute for cider production. The authority for the French cultivar classification families, for keeving as an industrial process, and for the pectin and nitrogen chemistry that keeving depends on.
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.
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.