Fault
Yeast haze
Cloudiness from yeast cells that have not settled out, usually because the strain flocculates poorly or the cider has not been left alone long enough.
Also called yeast in suspension, poor flocculation.
- Severity
- Cosmetic — looks wrong, tastes fine
- Where it starts
- Fermentation, Maturation
- Can it be fixed?
- Yes, if caught in time
- When you notice it
- Fermentation, Maturation, Packaging
- Signs
- 5 recorded
What it is
Yeast haze is the most benign of the clarity faults: cells still in suspension after fermentation, scattering light. It is often not a fault at all but a cider that has not finished settling. Where it persists, the cause is usually a yeast strain that flocculates poorly, a vessel that keeps being disturbed, or a cider that never got cold enough for the cells to drop. It clears with time, cold and stillness in a way that pectin and starch hazes do not.
What you notice
Grouped by sense, because that is how the fault presents itself rather than how it works.
To look at
- A soft, slightly grey or cream-coloured haze
- A compact pale sediment building at the base of the vessel
How the batch behaves
- A cider that clears steadily from the top down when left undisturbed — Progressive clearing from the surface is the signature of a settling haze rather than a colloidal one.
- Haze returning whenever the vessel is moved or the cider is poured carelessly
On the nose
- A faintly yeasty, bready note on the nose
The words for it: Fresh yeast, Lees. Each links to what produces it.
When it appears. Immediately after fermentation and after any disturbance of the lees. It clears with time and settling, which is what distinguishes it from every other haze on this list.
Time is both the test and the remedy: a haze that has not begun to settle after several weeks in the cold is not a yeast haze.
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 sediment — Where the yeast is. Suspended yeast is a haze; settled yeast is a sediment, and the same batch can show both.
- Microbial haze — Whether it clears. A yeast haze from the primary ferment settles; a spoilage haze does not, and usually smells.
- A bottle-conditioned cider poured through its deposit — Pour a second bottle carefully. Bottle-conditioned cider is meant to have yeast in it, and the haze is a pouring question rather than a fault.
A yeast haze is expected in bottle-conditioned cider and in anything drunk young from the cask. It is only a fault where the cider was supposed to be bright and has not become so.
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.
Flocculation is the property by which yeast cells adhere to one another and form aggregates heavy enough to sediment. It is genetically determined and strain-specific: cell-surface lectin-like proteins bind mannan residues on neighbouring cells, in a calcium-dependent way, when the cells enter stationary phase. Strains differ enormously, and some remain in suspension almost indefinitely.
Environmental conditions govern how quickly settling then occurs. Low temperature increases both flocculation and the density difference driving sedimentation; agitation and residual carbon dioxide evolution keep cells suspended; and vessel geometry matters, since cells in a tall narrow vessel have further to fall than in a shallow one.
Where the yeast is still fermenting slowly, gas evolution keeps stirring the cider gently and no settling occurs. A haze that will not clear in a cider believed finished is therefore worth checking with a hydrometer, because it may be describing an unfinished fermentation rather than a flocculation problem.
Non-Saccharomyces species behave differently again. Several of the wild yeasts present in a spontaneous ferment flocculate poorly and remain in suspension long after Saccharomyces has settled.
How it happens
| Cause | Stage | How often |
|---|---|---|
| A yeast strain selected without regard to its flocculation characteristics | Fermentation | common |
| Cider not left still long enough after fermentation | Maturation | common |
| A cellar that never gets cold enough for the cells to drop | Maturation | common |
| A slow fermentation still evolving gas and keeping cells in suspension | Fermentation | occasional |
| Vessels repeatedly moved, topped up or disturbed | Maturation | occasional |
| A spontaneous ferment with a mixed population of poorly flocculating wild yeasts | Fermentation | 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 |
|---|---|---|
| Leave the cider cold and undisturbed | Reliable | The whole answer in most cases, and it costs nothing but weeks. A cider that clears from the top down is doing what it should. |
| Rack off the settled yeast and let it clear again | Reliable | Repeated racking progressively brightens a cider. Each racking risks oxygen pick-up, so do it quietly and keep vessels full. |
| Filter the cider | Reliable | Removes yeast reliably. It also removes the population needed for bottle conditioning, so decide the order of operations before starting. |
| Accept the haze | Reliable | A cloudy cider with yeast in suspension is a recognised and traditional presentation, and nothing is wrong with the drink. |
| Fine the cider | Partial | Effective for stubborn yeast haze. Bench trial first and use the smallest effective dose from the supplier’s guidance, because finings remove aroma and phenolics as well as yeast. |
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
- Choose a yeast whose flocculation behaviour suits the intended presentation, using the supplier’s published characteristics.
- Confirm fermentation is complete before expecting a cider to clear.
- Leave the vessel undisturbed; every movement resuspends what has settled.
- Let the cider get cold, either by seasonal cellar temperature or deliberately.
- Rack carefully off the sediment rather than drawing it back into suspension.
Yeast haze belongs in a faults file mainly so that it can be distinguished from the hazes that matter. It is the one that time and cold resolve, and a maker who has learned to tell it apart from a pectin haze saves themselves both unnecessary treatments and pointless waiting.
The test is behavioural rather than analytical. Leave the vessel completely alone in a cold place for a fortnight and look at the top third: a settling haze clears from the surface downwards and leaves a visible deposit, and a colloidal haze looks the same at the end as at the beginning.
Where it genuinely will not settle, the most useful question is whether fermentation has finished. Slow gas evolution keeps yeast in suspension indefinitely, and a haze that resists everything is sometimes a hydrometer problem rather than a clarity problem.
It is also worth saying that clarity is a stylistic choice rather than a standard. Bright cider looks well in a glass and is what most commercial presentation aims at; cloudy farmhouse cider has a long and unapologetic tradition, and yeast in suspension contributes texture and a bready note that some styles depend on.
The compounds involved
Beta-glucan
The bacterial exopolysaccharide behind ropiness, which turns a cider oily and thread-like without changing how it smells or tastes.
Yeast-assimilable nitrogen
The nitrogen a yeast can actually use, which apple juice is chronically short of — the shortage behind both stuck fermentations and rotten-egg aromas, and the shortage keeving deliberately makes worse.
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.
The 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.
Saccharomyces bayanus
A name applied both to a hybrid *Saccharomyces* lineage and, loosely, to a whole class of commercial high-alcohol yeasts, and one of the least stable names in fermentation microbiology.
Hanseniaspora uvarum
The apiculate yeast most often reported from grapes and widely present on apples too, whose anamorph name *Kloeckera apiculata* still appears throughout older cider literature.
Torulaspora delbrueckii
A non-Saccharomyces yeast that ferments further than most of its early-succession neighbours while producing notably little acetic acid.
Candida species
A large, historically artificial grouping of yeasts that appears throughout cider microbiology, containing organisms with little in common beyond the absence of a sexual stage.
Where in the process it arises
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.
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.
Filtration
Passing cider through a porous medium to reach a stated visual brightness, at a real cost in colloidal material, body and aroma.
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.
Yeast selection
Choosing which cultured strain to pitch, on the basis of the temperature, nitrogen, alcohol and aroma behaviour that separates one commercial yeast from another.
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.
Faults it is confused with
These present similarly. What separates them is set out on each page.
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.
Pectin haze
A persistent, slightly viscous haze that will not settle, caused by pectin from the fruit remaining in solution as a colloid.
Microbial haze
Cloudiness caused by a growing population of spoilage organisms, and therefore a symptom of something worse rather than a clarity problem in itself.
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.
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.
- What yeast should i use for cider — CiderHQ does not recommend brands. The choice is between a neutral, reliable strain that lets the fruit show, an aromatic wine strain that adds its own esters, and no addition at all. Alcohol tolerance, cold tolerance and nitrogen demand are the properties worth comparing.
- How do i clear a cloudy cider
- 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.
- 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.
- 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.
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.
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.
Peer-reviewed literature on cider fermentation microbiology
Various journals · peer-reviewed literature · registered as competent for this subject
Covers the microbial succession of spontaneous cider fermentation, the role of non-Saccharomyces yeasts in the early stages, malolactic conversion by Oenococcus and Lactobacillus species, and the organisms behind the principal spoilage faults.