Fault
Excessive astringency
A drying, roughening, mouth-puckering sensation that outstays its welcome, produced by larger phenolic polymers precipitating salivary proteins.
Also called over-tannic cider, harsh grip.
- Severity
- Quality — the drink is worse for it
- Where it starts
- Blending, Pressing, Fruit preparation, Maturation, Fermentation
- Can it be fixed?
- Yes, if caught in time
- When you notice it
- Pressing, Fermentation, Maturation
- Signs
- 5 recorded
What it is
Astringency is not a taste but a tactile sensation: the feeling of the mouth being dried out and roughened, as though the surfaces have lost their lubrication. In cider it is produced by larger procyanidin polymers binding and precipitating the proteins in saliva. Like bitterness it is a defining feature of traditional cider and a fault only in excess — when the grip is harsh rather than structural, when it dominates the finish, and when it makes a second glass unappealing.
What you notice
Grouped by sense, because that is how the fault presents itself rather than how it works.
In the mouth
- A drying, rasping feeling across the gums and the inside of the cheeks
- A sensation that builds across successive sips rather than fading — Astringency accumulates because saliva is depleted faster than it is replaced.
- A finish that feels rough and stripped rather than long
- A puckering grip disproportionate to any bitterness present
How the batch behaves
- Cider that seems harsher at cellar temperature than when slightly warmed
The words for it: Apple skin, Unripe pear. Each links to what produces it.
When it appears. From the juice, and it softens over months as tannins polymerise and drop out. A young tannic cider is not the cider it will be in a year.
It builds across repeated sips rather than declaring itself on the first, so a single mouthful understates it. Assessing astringency properly requires more than one sip and a pause, which is the reason the tasting guides put it in the structure step rather than the aroma step.
Symoneaux, Baron, Marnet, Bauduin and Chollet, LWT — Food Science and Technology 57:22–27; and Symoneaux, Chollet, Bauduin, Le Quéré and Baron, LWT 57:28–34, Various journals
What it is mistaken for, and how to tell
One observation per rival, chosen because it separates them rather than because it describes either. Several of these are not faults at all — a style feature, a normal outcome, or the fruit behaving as it does.
- Excessive bitterness — Ask whether it is happening on the tongue or to the tongue. Astringency is texture; bitterness is taste.
- Excessive acidity — Acid makes the mouth water; astringency dries it. They are opposite responses and are routinely both called sharp.
- A young tannic cider — Time. Astringency that will resolve is the ordinary state of a bittersweet cider in its first winter.
- A perry pressed without a pomace stand — In perry, high astringency often traces to pressing practice rather than to the fruit, because standing the milled pomace before pressing leaves tannin behind deliberately.
A drying finish is characteristic of cider from high-tannin fruit and is one of the properties that distinguishes it from cider made from dessert apples. It is a fault where it dominates rather than where it is present.
What is actually happening
The chemistry or microbiology behind it. Understanding the mechanism is what makes the prevention make sense rather than being a list of rules.
Salivary proline-rich proteins are unusually flexible and expose many binding sites. Procyanidins associate with them through hydrogen bonding and hydrophobic interaction, and above a certain size the complexes formed become insoluble and precipitate. The loss of the salivary protein film is what is felt as astringency: it is a mechanical consequence rather than a chemical signal.
Binding strength rises with polymer size. Research on apple procyanidins has established that mean degree of polymerisation is the principal determinant of the split between bitterness and astringency: shorter chains bind salivary protein weakly and are perceived as bitter, longer chains bind strongly and are perceived as astringent. Cider apple procyanidins run to substantial chain lengths, which is why traditional cider is astringent in a way that grape wine at similar phenolic levels often is not.
Several other factors modulate the perception. Low pH increases astringency, partly by changing the protein and partly through the acid’s own effect on the mouth; ethanol reduces it; residual sugar reduces it; and polysaccharides — pectin fragments, yeast mannoproteins from lees ageing — interfere with the protein-tannin interaction and soften it.
Ageing reduces astringency by continuing the polymerisation until the largest polymers become insoluble and precipitate out of the cider entirely. This is why a hard young traditional cider softens over a year or two, and it is a real chemical change rather than an adjustment of perception.
How it happens
| Cause | Stage | How often |
|---|---|---|
| A blend dominated by high-tannin fruit with long-chain procyanidins | Blending | common |
| A cider tasted very young, before polymerisation and precipitation have run | Maturation | common |
| Hard pressing or an aggressive final pressing extracting from skins and pips | Pressing | occasional |
| Extended maceration of the pomace before pressing | Fruit preparation | occasional |
| A bone-dry finish with no sugar or glycerol to soften the sensation | Fermentation | occasional |
| Very low pH intensifying the perception | Blending | occasional |
Can it be put right?
Most cider faults cannot be reversed. Where that is the answer it is given plainly — an honest 'this batch is what it is' is more useful than a procedure that will not work.
| Option | Effectiveness | What it involves |
|---|---|---|
| Give the cider time | Reliable | The most effective and least destructive route. Polymerisation and precipitation reduce astringency substantially over a year or more, and it is what traditional practice has always relied on. |
| Blend with a low-tannin cider | Reliable | Works directly and predictably. Bench trial several ratios. |
| Fine with gelatin or a similar protein agent | Partial | Precipitates the largest procyanidins, which are precisely the astringent ones, so it targets the fault well. It strips aroma and body with them. Bench trial a dose range from the supplier’s guidance and choose the smallest that works. |
| Back-sweeten | Partial | Sugar reduces perceived astringency. Requires a stabilisation decision before the cider is packaged. |
| Serve slightly warmer and with food | Partial | Not a repair, but astringency is genuinely perceived as less harsh at a slightly higher serving temperature and against fatty or protein-rich food, which competes for the same binding. |
CiderHQ gives no additive dosage figures. An addition is a food-safety decision that depends on legal limits, on the juice in front of you and on what you are protecting against, and the right figure comes from your supplier’s or regulator’s own guidance rather than from a general reference.
Preventing it
- Blend with the finished cider in mind and bench trial the proportions rather than working from fruit classification alone.
- Match pressing pressure and maceration time to the phenolic content of the fruit.
- Plan for maturation time; traditional high-tannin cider is not meant to be judged at three months.
- Consider lees contact, which contributes mannoproteins that genuinely soften the sensation.
- Decide early whether the cider will carry residual sweetness, since that changes what level of astringency is acceptable.
Astringency and bitterness are routinely lumped together as tannin, and separating them is one of the most useful things a cidermaker can learn to do. Bitterness is tasted; astringency is felt. A cider can have plenty of one and little of the other, and the treatments diverge accordingly.
The size relationship is the key to the whole subject. Short procyanidin chains are bitter, long ones are astringent, and everything a maker does to a cider — pressing harder, macerating longer, ageing it, fining it — moves the size distribution and therefore moves the balance between the two sensations.
It also explains why traditional cider needs time in a way that a modern fresh style does not. The largest, most astringent polymers eventually become insoluble and drop out; a hard young bittersweet cider is not a mistake but an unfinished one, and judging it at six months is judging it before the chemistry has run.
Serving context deserves more credit than it usually gets. Astringency binds salivary proteins, and food rich in fat and protein offers alternative binding partners, which is the mechanism behind the traditional pairing of tannic cider with pork and hard cheese. It is not a fix for an over-tannic cider, but it is a real effect.
The compounds involved
Procyanidins
The condensed tannins of cider fruit, whose chain length — not their quantity — decides whether the mouth registers bitterness or astringency.
Epicatechin
The flavan-3-ol that apple procyanidins are almost entirely built from, and the most bitter of the phenolic monomers a cider contains.
Catechin
The minor flavan-3-ol of apple, present largely as the terminal unit of procyanidin chains, and consequently a useful analytical handle on chain length.
Total phenolics
The single number used to summarise everything phenolic in a juice, useful for comparing fruit and misleading whenever it is used to predict how a cider will taste.
Tannin–protein complexes
What astringency physically is: long tannin chains cross-linking salivary proteins and precipitating them, which is also the mechanism behind fining, protein haze and the classic cider-and-cheese pairing.
Glycerol
A syrupy three-carbon alcohol yeast produces as a side reaction of fermentation, which adds weight to a dry cider and is the raw material for one of its more obscure faults.
Where in the process it arises
Blending
Combining separate lots of cider or perry into one, which in cider is the historically normal way of making the drink rather than a remedy applied when single lots disappoint.
Tannin balancing
Setting the phenolic structure of a blend, which means handling bitterness and astringency separately because they are different perceptions produced by different sizes of the same molecules.
Bench blending trials
Making small measured mixtures of candidate lots and tasting them before committing tanks, because how components behave together cannot be worked out from how they taste apart.
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.
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.
Lees ageing
Deliberately holding a cider or perry on its fine yeast deposit so that autolysing cells release material that changes texture and foam behaviour.
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.
Faults it is confused with
These present similarly. What separates them is set out on each page.
Excessive bitterness
Bitterness that dominates the palate rather than supporting it, usually from a blend weighted too heavily towards high-tannin fruit or extracted too hard.
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.
Excessive acidity
Acidity high enough to dominate everything else, leaving a cider that is thin, hard and sour rather than fresh.
Where this comes up in a guide
The link lands on the step where the fault arises rather than at the top of the pathway, because that is where the decision that causes it is taken.
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.
- 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.
- 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 do you blend cider
- What are procyanidins in cider — They are the condensed tannins of apples: chains of catechin-type units whose length decides how much of the phenolic load reads as bitterness and how much as astringency. Two ciders with identical total tannin can taste nothing alike.
- Why is my cider so bitter
- Why is my cider so sharp
Where to go next
- The fault finder — Describe what you can smell and see, and narrow it down from the signs.
- All faults — Grouped by where they come from and how serious they are.
- Cider science — The chemistry and microbiology these faults come out of.
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.
Institut national de recherche pour l’agriculture, l’alimentation et l’environnement (INRAE)
INRAE · research institute · retrieved 2026-08-24
French national agricultural research. Its Angers programme produced much of the published work on apple procyanidin chain length and on the relationship between polymer size, bitterness and astringency.
Peer-reviewed literature on apple phenolics and cider sensory perception
Various journals · peer-reviewed literature · registered as competent for this subject
Registered as a class rather than as one paper, because the mechanisms CiderHQ describes — tannin chain length driving the split between bitterness and astringency, salivary protein precipitation, enzymatic browning — are established across many studies rather than resting on any single one. Individual papers are cited where a specific number is quoted.
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.