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GENERAL CHEESE MAKING BOARDS (Specific Cheese Making in Boards above) => STANDARD METHODS - Forming Cheese => Topic started by: Sue (aka Leah's Mom) on April 21, 2011, 06:37:13 PM

Title: Questions Regarding: Rule of Thumb for Pressing psi by Cheese Type
Post by: Sue (aka Leah's Mom) on April 21, 2011, 06:37:13 PM
Hello everyone!

I’m looking for a “rule of thumb” for pressing psi for specific cheese types.  I’ve looked through some of the old threads and haven’t seen what I’m looking for so I’m hoping to get some feedback on this issue.

I was recently looking at the book, “The Joy of Cheesemaking” by Jody Farnham and Marc Druart.  In the book they classify cheeses by family like this:

Cheese Family / Cheeses
Title: Re: Questions Regarding: Rule of Thumb for Pressing psi by Cheese Type
Post by: Scarlet Runner on April 22, 2011, 08:35:57 PM
You know, I spent a lot of time searching for the Holy Grail (eg precise psi's ideal for each type of cheese) and I did find some tidbits here and there on the forum.  But by and large, the message that I got from the forum was the goal of pressing is to get curds to knit so as to prevent molding and ensure the appropriate final texture. So the general guideline I eventually settled upon is press at whatever weight accomplishes this.  It's a sort of unsatisfying answer in some ways... but it makes sense and makes the whole thing easier in others. After making a Gouda, Cheddar and Jack, I have a fairly good sense of any modifications I want to make to pressing, based on the texture and knit.

I know that's not what you're seeking- and I could be dead wrong!-  so I'm curious  to see what others post here.  Thanks for this good question. 

PS I remember that others often post a website The University of Guleph or something like that, which has some pressing psi's for cheese types, in answer to questions of this sort.
Title: Re: Questions Regarding: Rule of Thumb for Pressing psi by Cheese Type
Post by: linuxboy on April 22, 2011, 11:06:05 PM
It's a sort of unsatisfying answer in some ways.
There is a right answer. If you narrow down the process to where all the variables that influence knit (vat dynamics, pre-pressing, calcium levels, hydration, milk PF, etc) are standardized, I can give you the exact PSI for each cheese. But that's too easy, and also misleading because it's as you said, the PSI is about knit.

I've posted general PSI levels before in multiple threads. They're in the same range as Marc's because that's what's used in the industry.

What is your opinion of the numbers here – do they sound right to those of you that have experience?
About right for commercial makes. At home, the curd kinetics are different. Or to put more simply, home batches tend to lose heat faster because the room temps are often lower, and because the curd mass is smaller. That means it sometimes takes more weight, especially when doing milled curd.
Have you ever seen a chart like this that is more comprehensive that lists more cheeses?  If so can you post it?
Yes, I made one, but it's useless to you without full make processes because the PSI for a cheese works in combination with the technology and timing of the make. Why do you need it? Not sure what the point is to have a chart just for a list of cheeses absent of their specifics. The best you could do without specifics is a general range like Marc included. Notice his are conversions from mercury readings because nobody using PSI does fractions... we typically go in .25 increments.
-Based on their “cheese family” list, would I take this to mean that the number stated for gouda would apply in general to all cheeses in the “semi-hard” classification such as Monterrey Jack?
No. Gouda is a special case because it is prepressed, needs less weight than jack. And other semi-firm cheeses you barely press at all... like tommes generally one does not press with more than 1 PSI, if that. You can make a generalization, though, that to achieve good knit without prepressing, one needs 3-8 PSI (not very useful as I said).

How would you classify cheeses like caerphilly and derby within these families?
Anything milled curd needs higher weight, usually at least 8 PSI. Anything not milled curd needs a range as mentioned earlier based on the make parameters.