Glossary · Chemistry
Patulin
Definition
A mycotoxin produced chiefly by Penicillium expansum in rotting apples, regulated in apple juice and apple products because of its toxicity. Sorting out rotten fruit is the principal control.
- Subject
- Chemistry
In more detail
Patulin is present in the fruit before milling and is not destroyed by pressing or by ordinary processing. Fermentation does substantially degrade it, so fermented cider generally carries far less than juice from the same fruit, but the regulatory limits and the food-safety reasoning are written around juice.
The practical implication for cider makers is that windfalls left to rot are a safety question and not only a quality one, and that a fruit-sorting table earns its cost.
Where this is covered properly
The glossary defines; these pages explain. Each is described in its own words.
Chemistry
Patulin
A mycotoxin produced by the blue mould that rots stored apples, regulated in apple juice worldwide, and the clearest food-safety reason not to press rotten fruit.
Production
Patulin control
Managing the mycotoxin produced by rot fungi in damaged apples, which is controlled by fruit selection rather than by any treatment applied to juice.
Microbiology
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.
Related terms
Terms that belong to the same part of the subject, or that this one is routinely confused with.
Fruit
Brown rot
A fungal rot of apples and pears, chiefly *Monilinia fructigena*, producing an expanding brown lesion with concentric rings of buff spore pustules. Affected fruit is unfit for milling.
Orchard
Fruit sorting
Removing rotten, mouldy and foreign material from harvested fruit before milling, by hand on a table or by flotation and mechanical inspection at scale.
Orchard
Windfall
Fruit that has fallen from the tree before deliberate harvest. In cider orchards windfalls are a normal part of the crop; the question is how long they have lain and in what condition.
Microbiology
Penicillium expansum
The blue-green mould of stored and damaged apples, producing a soft watery rot and the mycotoxin patulin. It is the organism that makes rotten fruit a safety question.
Where to go next
- Cider glossary — The whole vocabulary, by subject and A–Z.
- Comparisons — Terms that are only really clear when set against the thing they are not.
- Search — Finds terms by their aliases and by their spellings in other languages.
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.
European Food Safety Authority scientific opinions
EFSA · regulator · retrieved 2026-08-24
Registered for the food-safety questions cider genuinely raises: patulin in juice from rotten fruit, sulphite sensitivity, and the toxicology behind additive limits.
Codex Alimentarius food standards
FAO / WHO · standards body · retrieved 2026-08-24
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.