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Equipment

The scratter

What is a scratter and how does it break up apples?

In short

A scratter is a mill in which whole apples are dropped into a hopper and fall onto one or two rotating rollers set with teeth, spikes or knives, which tear them into coarse chunks and shreds. The name is a West Country word and it describes what the machine does: it scratches the fruit apart rather than cutting or pulping it.

Compared with a stone mill it is fast, cheap, small and needs no animal. Compared with a modern hammer mill it produces a coarser, more irregular pomace that drains well in a rack and cloth or basket press.

Scratters range from a hand-cranked wooden box to a belt-driven cast-iron machine handling a tonne an hour, and the working principle has not changed since the nineteenth century.

The mechanism

The classic form is a pair of horizontal rollers turning inwards towards each other, mounted a set distance apart in a frame, with a hopper above. The rollers may be studded with iron teeth, cut with coarse longitudinal ridges, or fitted with removable knife bars. Fruit falling into the nip is gripped, dragged through and torn. The gap between the rollers sets the coarseness: a wide gap gives large chunks and a poor press yield, a narrow gap gives finer pomace and more juice but a pomace that drains more slowly.

A single-roller variant uses one spiked drum working against a fixed breaker plate or comb, which is simpler to build and easier to clear when something jams. Many small modern mills are of this type, with a stainless or food-grade polymer drum.

Historic scratters were often built into a frame that also carried the press, so that fruit could be milled straight into the cheese below. Museum examples in Somerset and Herefordshire show wooden-bodied machines with iron rollers, hand or horse driven, and later cast-iron machines built by agricultural engineers for the farm trade.

What it does to the juice

Scratter pomace is coarse and structurally open. That is the property that makes it work in the presses it evolved alongside: chunks of apple in a cloth-wrapped cheese hold channels through which juice can escape under pressure, and a rack and cloth press will run freely on scratter pomace where it would seize on a fine purée.

The trade-off is extraction. Cells that are never ruptured never give up their juice, and coarse pomace leaves a measurable amount behind in the cake. It also extracts less phenolic material into the juice than a finer grind, because less cell wall surface is exposed, and it browns more slowly because there is less surface area meeting air.

A scratter run at a moderate gap, with the pomace left to stand for a period before pressing, is the arrangement most small traditional makers converge on. It gives enough particle reduction for a reasonable yield, enough structure for the press, and a controllable amount of maceration.

Practical points

Guarding and the hopper

A scratter is an unguarded set of rotating teeth at the bottom of an open hopper. Fruit is pushed down with a wooden stick or plunger, never with a hand or arm, and the drive is isolated before anything is cleared. Powered machines should not be run with the hopper removed.

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