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GENERAL CHEESE MAKING BOARDS (Specific Cheese Making in Boards above) => STANDARD METHODS - Forming Cheese => Topic started by: wharris on November 01, 2008, 06:03:55 PM

Title: Pressing Pressures
Post by: wharris on November 01, 2008, 06:03:55 PM
I am very new to cheese making.  I just made my first batch this week. I'm hooked.

But as I read and think about my equipment, I have a question about presses.

I see references to 10lbs of weight for 15 min, then increase to 40lbs for 12, then 50lbs for 24hours.
And, of course, for different cheeses, there are different recommendations.

But my question is this.  What does that 50lbs represent?  so.  for example.  if I have a 6 inch mold, 50 lbs on that press yields about 1.75psi.

Is that enough?  I don't think so.  But fact is, i don't know. 

A quick google does not yield any references to PSI for cheese recipes.  I see presses that can apply anywhere from 3-100 psi.   But, i don't see PSI settings in the recipes.

Thoughts on the correct PSI needed for a standard cheddar press??

Thanks.

Title: Re: Pressing Pressures
Post by: Cheese Head on November 01, 2008, 07:52:00 PM
Hi wharris and welcome to this forum.

It's a good question with no hard answer, as you say 50 lb on a 6" diameter cheese works out to 50/(pie x r2) = 1.7 psi, whereas 50 lb on a 4 " diameter hoop cheese is 4.0 psi, quite a difference.

The reality I think is the weights and durations in the recipes are guidelines only as there are many variables, how much whey have you removed before pressing, type of milk used, how hard a cheese you want after aging, how many holes does your hoop and base have to release the whey been pressed out, etc. So basically after you've done a couple of pressed cheeses you start to get a feel for it. Also, if you press at high weights for long time, there is normally very little whey coming out in last hours.

Hope this helps . . . John.
Title: Re: Pressing Pressures
Post by: wharris on November 03, 2008, 09:42:49 PM
Well,  I built my own Cheese press

(http://blufiles.storage.live.com/y1pkcB1pq5PKScSyOvEfgS06lud_fkxK5vIvimJ0ndLqgqRNe8fllLzuNIqDeSDKQ61)

The way I calculate it, i am going to use about 2.8psi using this much weight.

showing my work:
[(weight of bucket)*(distance multiple from plunger)]/(Surface area of follower)
(32lbs*2.5)/28.25sqin
80lbs/28.25sqin
2.83lb/sqin (psi)

I think i can get up to 7-10 psi if i really had to.  But the fact is, i really don't know what is needed.

Simply specifying X lbs of force, in a recipe is just not giving me a complete picture here.

I must read on.

Thanks for your reply.

Title: Re: Pressing Pressures
Post by: Cheese Head on November 03, 2008, 11:34:58 PM
wharris, thanks for the picture, looks great, nice and simple and mechanically stable, congrats!
Title: Re: Pressing Pressures
Post by: wharris on November 05, 2008, 01:29:15 AM
I was asked to refine my math.  so here it is:
showing my work:
Constants:
1 gallon of water = 8lbs
4gal=32lbs
Distance  between fulcrum and wall pivot: 12”
Empty press weight=29lbs

My formula for measuring PSI:
Pressure per square inch=[[(weight of bucket)*(ratio of fulcrum distances)+ Empty press weight]/(Surface area of follower)]

Bucket distance: 30" from the fulcrum, which is 2.5 times the 12" distance from the plunger to the fulcrum.
Cheese Mold diameter: 6" (radius 3")

So....
((32lbs*2.5)+29lbs)/(3.1415928*(3in^2))]
109lbs/28.25in^2
3.85 lbs/in^2 (psi)
Title: Re: Pressing Pressures
Post by: Tea on November 06, 2008, 08:36:03 PM
So how did the press work in the end.  Were you happy with the final result?  I must say that it certainly looks impressive.
Watching this one with interest.
Title: Re: Pressing Pressures
Post by: wharris on November 07, 2008, 02:55:59 AM
It turned out ok i guess.  i have not eaten it...I think i will wait 45 days or so.
Anyway, here is the press's first 2lb wheel of traditional cheddar.
(http://blufiles.storage.live.com/y1pdfRKtSHotRgiorRhbo9GzfSNUBsq0o5bqNqOYhdFnXWO9YK3kdJHAwe8mbGxWT4y)
(http://blufiles.storage.live.com/y1pcmZMiJILQWYHMhFvBBAdaehWG0USusuWdcxOqEjNByaiK45O97tNXxcLycG7CmNS)

Here is my processhttp://bocephus.spaces.live.com/photos/cns!8AD74B74B344340E!292 (http://bocephus.spaces.live.com/photos/cns!8AD74B74B344340E!292)
Title: Re: Pressing Pressures
Post by: wharris on November 07, 2008, 03:30:32 AM
I found an answer to my own question.
" Press with enough pressure to create a smooth rind by the next morning. This is 25 p.s.i. to start. After 30 minutes take of the pressure and tighten the cheese cloths around the cheese. Increase the pressure to 40 p.s.i. for the rest of the time."

http://www.dairyfoodsconsulting.com/recipes_cheddar.shtml (http://www.dairyfoodsconsulting.com/recipes_cheddar.shtml)
Title: Re: Pressing Pressures
Post by: Tea on November 08, 2008, 08:53:35 PM
Congrats Wharris that looks very professional.  Hope you can last the 45 days before you open it.  Keep us updated with the final results too please.  So what is the next cheese going to be?
Title: Re: Pressing Pressures
Post by: wharris on November 09, 2008, 01:55:26 PM
Next cheese?,  that is a great question. 
I have 6 gallons of milk ripening with MA11 for cheddar as I type this.
 
My son (17)has expressed interest a swiss varietal, and the the wife wants havarti.  I was leaning to a parmesan.

So,  I have a feeling its gonna be Havarti, Swiss, and Parmesan. 


In that order.

;)
Title: Re: Pressing Pressures
Post by: Tea on November 10, 2008, 07:24:03 PM
In regards to the havarti, are you waxing, or are you going to try the washed rind?  Just wondering, as I have been looking at a recipe for a while now, and wondering which way I should go.
Title: Re: Pressing Pressures
Post by: wharris on November 10, 2008, 08:44:00 PM
Funny,  I've been staring at this decision too. 

I am probably not going to wax.  I do not plan to keep the havarti for more than 90 days. 
Title: Re: Pressing Pressures
Post by: SalMac on November 22, 2008, 04:48:52 PM
Somehow I missed this entire thread, great great press! Good stuff!
Title: Re: Pressing Pressures
Post by: wharris on November 22, 2008, 11:37:12 PM
Just to cross the "Stockpots" thread Sal,  I used that press to apply 5.5psi to my 8in wide wheel of cheddar.
Title: Re: Pressing Pressures
Post by: wharris on December 01, 2008, 01:21:36 AM
I tweaked my press design.  I wanted to go to more PSI. 
I raised the lever arm up to over my head.
I used a longer "piston" arm
I installed a lower guide arm for stability.
(http://blufiles.storage.live.com/y1p29GdwmZ7AxGX8DZ90wX0R32lZ9UrhJniUxptTT_d3GpEv606kWsSIdf-XSOs5RzT)

This allows me to have a more stable piston.  This design will not allow the piston to slide away, or towards the wall.
(http://blufiles.storage.live.com/y1pAW_OgljxPp7uLxZep-ktXWTCyB7j9pke3vDJPxRyoRQ2ns7t-r5NNi1Bw6DW4H3Y)
This will also allow me to hang weight from the lever arm.
In this case, i am using a strap to hang one of my primary grape fermentation containers (32gal trash containers). 
The nice thing about it, is that my weight is only about 1 inch off the floor.  So if things break, it only fails 1 inch.

Without writing out all my calculations. (feeling lazy). I am getting 11.5psi, on my 8in wheel of traditional cheddar right now.

That is nothing compared to the 55psi that i heard they use for commercial Cheddar presses. 

 
Title: Re: Pressing Pressures
Post by: Tea on December 01, 2008, 08:39:12 PM
Good heavens, that thing looks serious.  Next problem will be whether the moulds will be able to handle the pressure?
Are you noticing a difference in the cheese texture with the one that you have used the greater PSI on?
Title: Re: Pressing Pressures
Post by: wharris on December 02, 2008, 12:41:40 AM
What i am noticing is that i get one solid curd on the  side facing the piston, and a bit of "open" curd on the other.

I did not flip my cheese this time around.
Title: Re: Pressing Pressures
Post by: Tea on December 02, 2008, 07:30:48 PM
Hence the reason for turning the cheese during pressing!
Title: Re: Pressing Pressures
Post by: Cartierusm on December 11, 2008, 10:06:57 AM
Wayne, you are figuring out PSI for the cheese not the force, which most recipes call for, i.e. Cheddar 50 pounds. Do you know what commercial recipes call for? Meaning if they are using larger molds do they still use 50 pounds or are they actually calculation PSI? As you know I built a pnuematic cheese press, so I'm trying to figure out which way to go. Thanks.
Title: Re: Pressing Pressures
Post by: wharris on December 11, 2008, 01:36:58 PM
I have done a fair amount to searching on this, and have come up rather short on specifics.
I think i have found that force and PSI are often used interchangible in forums and recipies.

I am trying to be rather specific on this. 

I am calculating PSI.  Not force.



Title: Re: Pressing Pressures
Post by: Cartierusm on December 11, 2008, 06:33:02 PM
OK, so let's start charting the results we get and post them here for the benefit for others.

So Wayne, should I take the diamter of a typical mold, 4", and the recipes force, 50 pounds, and use that as a starting point in PSI if I'm goint to be making larger wheels?
Title: Re: Pressing Pressures
Post by: bundy on December 13, 2008, 04:13:01 AM
i have followed this thread with intrest.in all the recipe books on cheese making i have read i have never seen a recipe calling for cheese to be pressed a X psi.i think we are making a simple process difficult.
i have just made a jack US recipe 900g mold ( 6" )ten pound for 15 min - 15 pound 30 min.- 40 pound 12 hours, what could be more simple.
Bundy
Title: Re: Pressing Pressures
Post by: wharris on December 13, 2008, 12:30:21 PM
Bundy,

It is entirely possible that you are correct. I have the ability to add too much rigor  to many things in my life. Wife reminds me of this constantly.  ;)

But let me ask you these hypothetical questions Bundy.

What if you were asked to take your jack recipe to make a substantial wheel of cheese. Lets say a bigger 8-10kg wheel that is 14-18 inches in diameter.

or

What if you were asked to take your jack recipe to make a bunch of small tiny wheels (as presents or stocking stuffers!), that were only 2-3 inches in diameter.

Would you still use the same weight for each recipe variation?

I would imagine, (and i am no expert), that a consistent PSI would be the only way to make the adjustments to the different sized wheels.

Your recipe indeed calls for psi settings of: .3537psi for 15min, .5306psi for 30min, and finally 1.415psi for 12 hours.   If you wanted to scale up, or scale down your wheel size, then using your recipe psi figures, it is easy to figure out how much weight to add to your big wheel, or how much weight to take off for your tiny wheels.

And some recipes do in-fact call for PSI.  Peter Dixon (http://www.dairyfoodsconsulting.com/recipes_cheddar.shtml) is an example.

Yes,  perhaps i overthink it. 

But for me, the constant tinkering, the constant processes improvement,  is at least half the allure of cheesemaking.

Title: Re: Pressing Pressures
Post by: Cartierusm on December 13, 2008, 06:41:42 PM
Bundy, I think, with me at least, you missed the point. I'm using a pneumatic cylinder press. Meaning I'm using air, measured in PSI, to press the cheese. Normally with my old manual press I would just use weight and deal with PSI.
Title: Re: Pressing Pressures
Post by: bundy on December 13, 2008, 08:15:30 PM
i make cheese for my family,so i make cheese in 8ltr batches.and have allways kept to the kiss principle.
i do not even think or have facility to make 10kg wheel, as for smaller i would use same weight.
as for pneumatic cylinder i can see you would use psi.
Bondy
Title: Re: Pressing Pressures
Post by: Tea on December 14, 2008, 08:44:10 PM
And therein I think lies the problem with most of us.  We are either only making for family and friends, and even if we did get lucky and get the opportunity to sell, it most likely would still only be smaller rounds, and quantities.  The thought of making a 50lb wheel of cheese is way out of the reach of most people, in terms of quantity of milk and equipment required.

But still this has been interesting, as there are time where I might divide a 10ltr batch into 4, and press four smaller cheeses, and other times where I will leave the same cheese in one mould and press, so the question is, does the larger cheese require more pressure, or do the smaller cheese require less pressure.  Or in small quantities like I am doing, does it effect the cheese to any great extent at all?

Thinking, thinking, thinking...
Title: Re: Pressing Pressures
Post by: Cartierusm on December 14, 2008, 09:19:20 PM
I think definately you would need more weight (force) for doing larger wheels.
Title: Re: Pressing Pressures
Post by: the_stain on May 05, 2009, 02:53:01 PM
Peter Dixon's recipe led me to search the forum on PSI and found this thread.  I have nothing really constructive to add, other than to say, wow.  Dixon says to press cheddar at 40psi.  By my calculations, for a 4" wheel of cheese this would require slightly more than 500 pounds of weight!  That seems a bit crazy to me, considering most home cheddar recipes I've seen call for 1/10 that much.   Interesting topic to say the least.
Title: Re: Pressing Pressures
Post by: wharris on May 05, 2009, 06:07:51 PM
I have, since posting this original thread, pressed an 8" wheel with 19psi.

The results are still pending.  But I will say this, I bent my follower in the process.
Title: Re: Pressing Pressures
Post by: Cheese Head on May 06, 2009, 02:24:31 AM
Stain, I think those higher pressures are only possible with leverage as heavy weights like you say become unmanageable.

Wayne uses a levered press bolted onto 2x4" studs, there are many pictures of old presses in this thread (http://cheeseforum.org/forum/index.php/topic,1198.0.html) in case you get the urge to really get serious ;D.
Title: Re: Pressing Pressures
Post by: Cartierusm on May 10, 2009, 06:29:56 PM
Stain, are you sure he's talking about 40 pounds per actual square inch or 40# total for a 4" wheel? Most recipes in a book are already calculated for you for a 4" wheel.
Title: Re: Pressing Pressures
Post by: Foodieguy on July 31, 2009, 06:49:40 PM
Wayne...I built a similar version of your press. Works like a charm. To prevent the follower from twisting or moving I made sure it was level. I also added a couple of 3" screws to the bottom and top of the wall stud. :)
The arm weighs in at 25#, so I used weights in the beginning and moved to the arm with some #10 cans of tomato sauce. I will make up some water jugs in the future to I know my weights are consistent.


Now, for the conversation about psi or pounds.

They are the same thing in this regard.
If you have 4psi on a 4" mold and you convert the recipe from a 2Gal to a 20Gal, that would go into a much larger mold. When you go to press the curd, you are going to need the same "mass"/weight across the complete surface of the cheese face.
Also if you were to take an industrial recipe and make into something smaller, you would have to convert  psi to pounds in reverse.
Your one common factor here is the pounds per square inch. If you have a 4" mold or a 400" mold you will always have to apply the same PSI. With some "simple" math one can figure out how much more weight is needed to apply the correct PSI.

 
Title: Re: Pressing Pressures
Post by: wharris on July 31, 2009, 10:31:01 PM
Congrats on the press. I hope it works out for you.  I have come to hanging weight undee the lever arm.  Its safer.

As far as PSI is concerned, It sounds like you an I are on the same wavelength. 

As long as you keep the same pounds per square inch, you can adjust mould follower to any size mould.

The bottom line is that more square inches in your follower, the more pounds will be required to maintain that same ratio.

Title: Re: Pressing Pressures
Post by: wharris on July 31, 2009, 10:34:03 PM
One more thing, 

Send Pics!