Botrytis cinerea

Polyphenol oxidase

The copper enzyme that turns cut apple brown within seconds, and the reason a cidermaker has to decide, at the press, whether to let the juice oxidise or to stop it.

Beta-glucan

The bacterial exopolysaccharide behind ropiness, which turns a cider oily and thread-like without changing how it smells or tastes.

Pectin lyase

The chain-cutting activity in a commercial pectinase preparation, which raises press yield and clears a juice by destroying the colloid pectin creates — and destroys the possibility of keeving in the same stroke.

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.

Oxidation

The cumulative effect of oxygen on finished cider: fruit aroma flattens, colour deepens towards amber, and a bruised-apple or sherry-like character replaces the fresh one.

Enzymatic browning

The rapid darkening of milled fruit and fresh juice as polyphenol oxidase converts phenolics to quinones, taking colour and some tannin structure with it.

Colour loss

A cider left noticeably paler than it should be, usually because fining, filtration or sulphite has removed the phenolic material that gave it colour.

Mould taint

Musty, earthy, cellar-damp or rotten-fruit character carried in from mouldy fruit or from mouldy equipment, and a marker that the patulin question needs asking.

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.

Gushing

Cider that erupts from the bottle on opening, either because it is over-pressurised or because something in it is nucleating the dissolved gas violently.

Patulin contamination

Contamination of juice or cider with patulin, a mycotoxin produced by *Penicillium expansum* in rotting apples — a genuine food-safety question rather than a flavour one.

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.

Fruit storage before milling

Holding a gathered crop between harvest and the mill, and managing what respiration, water loss and spoilage do to it while it waits.

Pest and disease management

Keeping scab, canker, rots and the main insect pests to a level the orchard can carry, at a cosmetic standard well below dessert fruit but without allowing rot into the crop.

Juice clarification

The deliberate use of enzyme, fining agents or mechanical separation to produce a bright juice before fermentation, and what that costs the ferment.

Filtration

Passing cider through a porous medium to reach a stated visual brightness, at a real cost in colloidal material, body and aroma.

Pectinase treatment

Adding pectin-degrading enzyme preparations to juice so that haze-forming and viscosity-forming pectin is broken down before fermentation.

Sulphiting

Adding sulphur dioxide to juice to suppress spoilage organisms and oxidative browning, at a level that only means anything once the juice pH is known.

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.

Sweating the fruit

Deliberately heaping or storing gathered fruit so that it softens, loses water and finishes converting starch before it goes to the mill.

Fruit washing

Removing soil, grass, stones and surface contamination from gathered fruit, usually in a water flume, before it reaches the mill.

Windfall management

Deciding which fruit that has reached the orchard floor can be used, and getting the rest out of the crop before it becomes a patulin problem.