Fault
Sorbate off-flavour
A faint plastic, candle-wax or celery-like note from sorbic acid used as a preservative, distinct from the geranium taint that bacteria produce from it.
Also called sorbate character, preservative note.
- Severity
- Quality — the drink is worse for it
- Where it starts
- Stabilisation, Blending, Storage
- Can it be fixed?
- Yes, if caught in time
- When you notice it
- Stabilisation, Packaging, Storage
- Signs
- 5 recorded
What it is
Sorbate off-flavour is the character sorbic acid itself contributes to a cider when it is used at a level people can detect. It is subtler than geranium taint and quite different in kind: a faint waxy, plastic, candle-like or vaguely celery-like note, sometimes with a slight bitterness, rather than the shrieking green of a geranium leaf. The two are often conflated, and separating them matters because they have different causes and different implications.
What you notice
Grouped by sense, because that is how the fault presents itself rather than how it works.
On the nose
- A waxy or candle-like note in a sweetened cider
- A faint plastic or synthetic edge that is not fruit
- A vaguely celery-like or vegetal impression
On the palate
- A slight bitterness or chemical edge in the finish
How the batch behaves
- The character present from the moment the preservative was added, rather than developing over weeks — This is the distinction from geranium taint, which develops as bacteria convert the sorbate.
The words for it: Plastic. Each links to what produces it.
When it appears. After a sorbate addition. It is present from that point and does not resolve.
The presence of sorbate is knowable from the record rather than from the glass, which makes this one of the easiest faults on the list to confirm or exclude outright — and one of the few whose prevention is a single decision rather than a practice.
Andrew Lea, Peter Mitchell / Cider and Perry Academy
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.
- Geranium taint — Whether lactic bacteria were present. Sorbate alone gives a synthetic, slightly plastic impression; sorbate plus lactic bacteria gives the distinct geranium note, which is much worse.
- Plastic and packaging taint — Whether sorbate was added. Both read as synthetic; only one is traceable to a component.
- A commercially back-sweetened cider — This is often simply what a chemically stabilised sweet cider tastes like, and the finding is about the method rather than about a mistake.
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.
Potassium sorbate dissociates in cider to sorbic acid, the active form. Sorbic acid inhibits yeast by disrupting membrane transport and interfering with several enzymes; it has essentially no effect on lactic acid bacteria, which is the fact behind geranium taint.
Sorbic acid has its own odour and taste at higher concentrations, generally described as waxy, plastic or faintly celery-like. Sensitivity varies between individuals, so a cider that seems clean to the maker may carry a detectable preservative note for someone else.
It also degrades slowly, particularly with warmth and time, producing carbonyl compounds and other breakdown products that contribute to the same general impression. A sorbated cider therefore tends to become slightly more marked in this respect over a long shelf life.
The related but separate fault is geranium taint, in which lactic acid bacteria reduce sorbic acid to sorbinol, which then reacts with ethanol to give 2-ethoxyhexa-3,5-diene — a compound of far lower threshold and far greater destructiveness. That is a microbiological event; this record covers the preservative itself.
How it happens
| Cause | Stage | How often |
|---|---|---|
| Dosing by habit rather than by calculation for the batch volume | Stabilisation | common |
| Sorbate used at a level near or above the sensory threshold | Stabilisation | occasional |
| Repeated additions to a cider that seemed unstable | Stabilisation | occasional |
| A delicate, low-tannin cider in which there is little to cover the note | Blending | occasional |
| Long, warm storage allowing the preservative to degrade | Storage | 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 |
|---|---|---|
| Use a different stabilisation route next time | Reliable | Filtration or pasteurisation avoids the question entirely, and for a cider whose character matters this is usually the better decision. |
| Blend into a larger volume of cider that has not been sorbated | Partial | Works because the perception is threshold-dependent. It also lowers the preservative concentration, so the stability the sorbate was providing is reduced accordingly. |
| Wait for the character to fade | Unlikely to work | The compound does degrade slowly, and its breakdown products contribute to the same impression, so time does not reliably improve it. |
| Remove sorbate from finished cider | Not possible | There is no practical method. |
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
- Consider whether sorbate is needed at all; filtration or pasteurisation stabilises a sweetened cider without introducing a preservative note.
- Where it is used, take the addition from the supplier’s guidance and from the legal maximum that applies, and calculate it for the batch volume rather than estimating.
- Use it alongside an effective sulphite level, which both improves the stabilisation and prevents the geranium route.
- Do not make repeat additions on the assumption that the first did not work.
- Store finished cider cool, which slows degradation of the preservative.
Sorbate off-flavour is a minor fault included largely so that it can be told apart from a major one. A maker who finds an odd chemical note in a sorbated cider needs to know whether it is the preservative itself, which is a matter of dose and taste, or the beginning of geranium taint, which means the batch is being lost.
The timing distinguishes them. The preservative note is present as soon as the addition has mixed through; geranium taint develops over days or weeks as bacteria work on the sorbate. A cider that was clean and has become sharply green over a fortnight is describing the second.
The broader point is that sorbate is a narrower tool than it is usually treated as. It stops yeast and does nothing to bacteria, which means it is never a complete stabilisation on its own, and it carries its own sensory cost. For a cider where character matters, filtration or pasteurisation is usually a better answer.
None of this is a claim about safety. Sorbate is a widely permitted preservative used across the food industry within regulated limits, and a cider carrying a detectable sorbate note is a cider that tastes of preservative, not one that presents a hazard.
The compounds involved
Sorbic acid
A preservative that stops yeast but not bacteria, and whose effectiveness — like that of sulphur dioxide — depends on pH, because only the undissociated molecule works.
Potassium sorbate
The soluble salt in which sorbic acid is actually added, used to hold sweetness in a bottled cider, and dangerous to use without sulphite because of what lactic bacteria do to it.
Benzoic acid
A weak-acid preservative added as sodium benzoate, more useful the lower the pH, and encountered in cider mainly in low-alcohol and soft products rather than in traditional ones.
Ethanol
The alcohol yeast makes from fruit sugar, which converts a perishable juice into a keepable drink and carries most of its aroma to the nose.
Where in the process it arises
Sorbate stabilisation
Adding potassium sorbate to prevent yeast from restarting a fermentation in the package — an inhibitor rather than a killer, and one that must never be used without sulphite.
Back-sweetening
Adding sugar, juice or concentrate to a cider that has fermented dry — a straightforward adjustment that leaves the drink microbiologically unstable until something is done about it.
Sulphite stabilisation
Managing free sulphur dioxide through maturation and at packaging so that a useful antimicrobial and antioxidant fraction survives into the bottle.
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.
Pasteurisation
Heating cider enough to inactivate the organisms that would spoil it, either in the sealed package or in-line before filling, at a measurable cost in fresh aroma.
Faults it is confused with
These present similarly. What separates them is set out on each page.
Geranium taint
A sharp, unmistakable crushed-geranium-leaf smell produced when lactic acid bacteria metabolise sorbic acid added as a preservative.
Plastic and packaging taint
Plastic, rubber, adhesive or chemical notes picked up from unsuitable containers, liners, hoses, gaskets or cleaning residues.
Excess sulphur dioxide
A struck-match or burnt-match aroma and a prickle at the back of the nose from too much free sulphur dioxide, with a real health consideration for sulphite-sensitive people.
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.
How cider is made, start to finish
How is cider actually made?
How to taste cider and perry
How do I taste cider properly?
When the fermentation is not doing what it should
My fermentation is doing something strange. What is going on?
Your first batch of cider
I have apples and no equipment. What do I actually do?
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 many calories are in cider — Roughly 40 to 60 kcal per 100 ml for most ciders, so a UK pint falls somewhere around 200 to 250 kcal. Alcohol contributes about 7 kcal per gram and residual sugar about 4, so both strength and sweetness matter.
- How do i make my cider sweeter
- How do i sweeten cider without it fermenting again — Either remove or kill the yeast — sterile filtration or pasteurisation — or use a non-fermentable sweetener. Sorbate alone is not enough: it prevents yeast multiplying but does not kill what is already there, and needs sulphite alongside it.
- Can i drink cider if i react to sulphites — Sulphite sensitivity is real but uncommon, and is most often reported in people with asthma. CiderHQ cannot give medical advice; what it can say is that ciders made without added sulphite exist and are labelled as such.
- What is geranium taint — Geranium taint is a pungent geranium-leaf smell produced when lactic acid bacteria metabolise sorbic acid. It is the specific hazard of sorbating a cider that still carries live lactic bacteria.
- How is cider pasteurised
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.
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.
Australia New Zealand Food Standards Code
Food Standards Australia New Zealand · standards body · retrieved 2026-08-24
Standard 2.7.3 covers fruit wine and cider, and defines what may be sold under those names in Australia and New Zealand.