Some cheese recipes state a weight to put on top of the mould prescribed in the recipe.   Others instruct you to put a certain pressure on the cheese.   

Pressure is the force (such as a 15 Kg weight) spread over an area (such as the top of a 13cm diameter mould). If your recipe just says put 15 Kgs on it then you just set up the press to deliver 15 kgs onto the follower plate of  your mould. If your recipe states a pressure of 5 pounds per square inch (psi) because they're American and can't help it, you can convert this to Kg per square centimeter (Kg/cm2) and that is .352 Kg/cm2.

 

Here is a simple on-line converter link http://www.cleavebooks.co.uk/scol/ccpress.htm

Pressure is force spread over an area - you need to know the area of your cheese mould top.   Remember 'pi'?!

'pi' times the square of the radius gives the area of a circle?!   Okaaaay - let me work it out for you. - here's a table of Round cheese mould diameters and their areas in cm2.

Diameter in cm 8 9 10 11 12 13 14 15 16 17 18 19 20 22 24 28 30    
Area in cm2  50  64  79  95  113  133  154  177  201  227  254  284  314  380  452  616  707    

 Your 13 cm cheese-mould has an area of 133 cm2.   and we need .35 Kg force on every one of them (to equal 5 psi).   That would be a force of 133 x .35 kg which equals 47 Kg.  47 Kg is easily supplied by the SturdyPress onto the top plate of your mould!

But Bob Samuelson has written an easy on-line calculator to help!  Try it!