Glossary · Fruit
Brown rot
Definition
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.
- Subject
- Fruit
In more detail
Brown rot enters through wounds and spreads by contact in store and in heaps, mummifying fruit that then overwinters on the tree as an inoculum source. It is a different organism from Penicillium expansum, the blue-green rot behind patulin, but both arrive by the same route and both are removed by the same sorting.
Where this is covered properly
The glossary defines; these pages explain. Each is described in its own words.
Microbiology
Monilinia fructigena
The brown rot of apples and pears, recognisable by concentric rings of buff pustules, and a major cause of fruit loss between the orchard and the mill.
Production
Fruit sorting
Taking rotten, mouldy and damaged fruit and foreign material out of the crop before it reaches the mill, which is the primary control on patulin in cider.
Related terms
Terms that belong to the same part of the subject, or that this one is routinely confused with.
Chemistry
Patulin
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.
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.
Orchard
Scab
A fungal disease, caused by *Venturia inaequalis*, producing olive-brown blotches on leaves and corky, cracked lesions on fruit. It reduces yield, disfigures fruit and opens the way for rots.
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.
NIAB (incorporating East Malling Research)
NIAB · research institute · retrieved 2026-08-24
East Malling developed the M-series apple rootstocks that determine tree size in essentially every modern orchard, cider orchards included. The authority CiderHQ uses for rootstock behaviour.
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.