Making a Press

The following information is taken from the out-of-print Agriculture Canada booklet # 1406 which was scanned by Bill at the Squeeze Cider Press (now closed) on Vancouver Island.  You can read the entire leaflet here. The full leaflet also contains details of how to make a mill at home, how to make and sterilise juices, and how to make straightforward fermented fruit wines and ciders.
Here are the details of the press:

A, Hydraulic jack, 1 1/2 tons capacity, 8-in, lift.
B, Jack support, a 14 x 14-in, piece of 3/4-in, fir plywood or hardwood with 6 slats 1/4 x 1 in. nailed on one side.
C, Racks. Five racks 14 x 14 in. are made from 1/4 x 1-in, slats of hardwood nailed to 1/4 x 1 1/2-in, slats at the edges. The center slat is 18 in. long and serves as a guide between the uprights, I. It is 2 in. wide and has a center slot. The nails are stainless steel.
D, Press cloths of medium factory cotton are about 36 in. square.
E, Press base is a 17 x 17-in, piece of 3/4-in, plywood fastened to supports G. A 14 x 14-in, piece of 1/2-in, plywood is centered on the larger piece to channel the juice to the outlet, F. Four slats 1/4 x 1 1/2 in. on edge form the sides around the base.
F, Juice outlet made of 3/4-in., acid- resistant or plastic pipe.
G, Supports for press base.
H, Press top is of hardwood or fir plywood with a metal plate at the point of contact of the jack.
I, Uprights are reinforced with 1/4 x 4-in, metal strapping across the press top and 20 in. down two sides. All uprights and cross pieces are made of 4 x 4-in, fir.
J Cheese form is 2 x 14 x 14 in. and is made from 3/4-in, hardwood. All wooden parts of the press that come in direct contact with the juice are coated with hot paraffin.

Boil new cotton cloths in water for 5 min and rinse. Dampen them before use. After each use, wash the cloths thoroughly by changing the water often and dry them well before you store them. To use the press, place a rack on the press base. Put the cheese form on the rack and cover both with a press cloth.

Pour the product to be pressed on the cloth, as shown, to make a cheese 2 in. thick. Fold the cloth neatly into the center of the cheese and remove the

cheese form. Place another rack above this cheese and repeat the procedure until there is only space for the jack support, B, and the jack. Center the jack on the jack support and apply pressure evenly.
Note there’s a similar set of plans and a clearer diagram given in the Proulx and Nichols book

My own press was virtually identical to this except that it’s somewhat scaled up.  I used 6″ square ash timbers, an 18″ square set of racks and cheese form (to give a 16″ square press area) and an 8 tonne jack.   Here’s the press in action.

People often ask about the pressures and yields associated with these sorts of pack presses.  A rough guide from calculation and my own experience is as follows:

• The original Canadian design (above) with 12.5″ effective square cheese and 1.5 ton jack gives 22 psi.
• My home-made variant with 16″ effective square cheese and a 2 ton jack gives 120 kPa or 17 psi and a juice yield ca 60%. This is a low yield, and I often used to re-wet the pomace (add about 10% by weight of water) and re-press when I was using this jack, to improve the yield.
• The same with a 4 ton jack gives 240 kPa or 35 psi and a juice yield of about 65%
• The same with an 8 ton jack gives 480 kPa or 70 psi and a juice yield of about 70%.  Generally I didn’t find it was worth wetting and re-pressing the pomace once I was using this jack.
• A commercial steel-framed hobby hand screw press (like Vigo) gives ca 788 kPa or 115 psi
• My commercial Voran press (steel frame and electric hydraulics) gives 952 kPa or 138 psi. JuiceYield ca 75%.

Yield is not a linear function with pressure and only increases by about 5% with each doubling of the pressure.  If possible it’s worth aiming for a minimum 70% juice yield and hence a minimum pressure of about 70 psi.  When you get to double that (like the commercial press at 138 psi) you can get adverse effects like pulp oozing through the press cloth if you’re working with soft dessert fruit . So excessive  pressure is not necessarily a good thing.  The other thing that influences yield is time. Most of the juice comes out fairly quickly but if you can maintain the pressure for several hours you can get a useful extra few % of juice. It all depends on how desperate you are and how much fruit you have!