The beam press, the screw press and the twin screw

A beam press is an enormous class-two lever. A baulk of oak, sometimes ten metres long, is hinged into a wall or a pair of posts at one end. The cheese sits under the beam close to the hinge, so the mechanical advantage between the load and the far end of the beam is large. Force is applied at the free end, either by hanging a weight — a stone block, a box of rubble — or, in the developed form, by a great wooden screw fixed to a stone counterweight, so that turning the screw hauls the beam down and lifts the stone.

The virtue of the arrangement is that a stone weight applies a constant, entirely patient force. As the cheese consolidates and the beam descends, the weight follows it, and pressing can be left overnight without anyone touching it. The vice is that everything about it is huge and immovable, and the pressure cannot be varied quickly.

Beam presses were the standard in monastic and manorial cider making and survived on large farms into the industrial period. Surviving examples are mostly in museums and a few in working use at heritage sites, since the building has usually gone with them.

The screw press substitutes a threaded spindle for the lever. A heavy frame carries a fixed crosshead through which a screw passes, and the screw bears on a follower block resting on the cheese. Turning the screw — by a bar through the head, by a capstan, or through a ratchet — drives the follower down. Early screws were cut from a single piece of elm or apple wood; later ones are cast or forged iron with an acme or square thread.

Force is applied in increments and has to be renewed. Pomace consolidates continuously, so the operator turns the bar, waits for the flow to slacken, turns again, and repeats over a period of hours. A press left untouched simply stops working as the cheese relaxes away from the follower. This is the fundamental difference in feel between a screw press and a hydraulic one: the hydraulic ram holds pressure by itself, the screw does not.

John Worlidge, writing in the 1670s, describes press construction and mill design in detail and is the earliest full English account of the arrangements. His interest was in making the equipment small and cheap enough that any farm could own it, which is a recognisably modern concern.

A twin-screw press puts two screws at either end of a movable crosshead, with the cheese built between the frame uprights below. It solves two problems at once. The pressing force is spread across a wider platen, so a larger and squarer cheese can be built; and the two screws can be turned alternately, which lets one person keep the load rising without the enormous effort of a single large screw.

It also keeps the platen roughly level. A single central screw pressing a tall cheese tends to tip if the cheese is built unevenly, and a tipping cheese sheds pomace out of one side — the classic failure that ends with pulp across the floor. The twin-screw geometry resists that.

The form is strongly associated with Normandy and Brittany, where large twin-screw presses in timber were standard farm equipment, and it appears in the English West Country too. Museum collections in Hereford and Somerset hold both the single and the twin form, alongside the combined mill-and-press frames that small farms used.

A slow press is an oxidising press. Juice runs across open timber and down open channels in contact with air for the whole run, and the cheese itself is exposed on all four sides. Combined with the long maceration that traditional milling implies, this is a large part of why farmhouse cider is dark and soft rather than pale and sharp.

Yield from a well-built cheese under a screw press is respectable but rarely matches a modern press, because the operator runs out of patience or thread before the cake runs out of juice. Historically the shortfall was recovered by breaking the cake up, rebuilding it and pressing again, or by watering the pomace and pressing a second, weaker liquor for farm consumption.