I'm getting a cheese press built and I need to know the range of PSI it should be able to handle. Now, I've done some searching through the forum and although I see this question asked repeatedly, by the time I get done reading the thread it seems the replies contradict themselves.
So then I decided to look through a couple of the cheese books I have: (
"Artisan Cheese Making at Home" and (B) "200 Easy Homemade Cheese Recipes". Book A is quite clear that the weights they recommend are NOT given in psi. In other words they are not dividing by the surface area of the follower. Book B is also quite clear that the weights they recommend ARE given in psi. But when you convert book A into psi the differences are extreme.
Here's an example of both book's Parmesan recipes.
A - Press @ 10# for 30 min, then press @ 20# for 12 hours. The recipe specifies a 8 tomme mould to be used so that means .19psi for 30 min then .39 psi for 12 hours
B - Press @ "medium pressure" (the book defines this as 10-20psi) for 30 minutes, then "very firm pressure" (the book defines this as 40-45psi) for 12 hours.
As you can see the differences are massive. So what PSI should I be looking to press hard cheeses at? Fractions of psi, or 40-50 psi?