Author Topic: Consequences of pressing too hard  (Read 8143 times)

mjr522

  • Guest
Consequences of pressing too hard
« on: March 06, 2013, 03:49:07 AM »
I used to follow the pressing schedules recommended by recipes.  Now, I just press every cheese I press with the same pressure--as much as I can get.  Besides the following that I've already found/thought of, what consequences are there of pressing a cheese too hard?

- curd extrusion
- embed the cheese cloth into the cheese
- break your mold/follower
- break your press
- waste effort using more pressure than is necessary...

I read somewhere recently that subjecting a cheese to crazy amounts of pressure (MPa/140psi+) speeds up the rate of maturation--something up busting up the bacteria so they release their innards faster.  It seems if you can do that to a cheese, then me putting a twice or three times the recommended pressure on a cheese won't make a lick of difference.

Thoughts?

Offline Tiarella

  • Old Cheese
  • *****
  • Location: Chester, MA, US
  • Posts: 1,748
  • Cheeses: 81
  • Default personal text
    • Farm Blog
Re: Consequences of pressing too hard
« Reply #1 on: March 06, 2013, 12:37:24 PM »
Well, I'd like to return the helpfulness but am not surely I have much to offer......
One issue of pressing with too much weight is that the acidification of the some cheeses, that stage of it that normally happens in the first light pressings, is missing from the make and will impact the results?  Hope someone with some knowledge will chime in.

That might even be an issue with some of my cheeses lately....not that I use a lot of pressure but that instead of hooping tommes under just the weight of their own curd I have used some weight in an attempt to make sure ai get a good knit.  Hmmm.

Offline Boofer

  • Old Cheese
  • *****
  • Location: Lakewood, Washington
  • Posts: 5,015
  • Cheeses: 344
  • Contemplating cheese
Re: Consequences of pressing too hard
« Reply #2 on: March 06, 2013, 02:24:58 PM »
I used to follow the pressing schedules recommended by recipes.  Now, I just press every cheese I press with the same pressure--as much as I can get.
I built my Dutch cheese press with the understanding that there might be occasions where I'd want to apply inordinate pressure on a specific cheese, like a Double Gloucester with "calculated pressure of 575lbs and 13.7psi". Other cheeses might not even go into the press, but would be pressed on the counter with 10 lbs (4.5 kg) or in the pot with 5 lbs(2.26 kg).

So the idea of pressing all cheeses with the same level of power eludes me. ???  Different cheese styles require different levels of density and residual curd moisture. IMHO, the idea of pressing is not necessarily to remove whey, but rather to cause the curds to adhere to each other...knitting. According to people in the know (linuxboy, Sailor, etc.), most of the whey that needed to be removed prior to pressing was accomplished with cooking and stirring.

-Boofer-
Let's ferment something!
Bread, beer, wine, cheese...it's all good.

mjr522

  • Guest
Re: Consequences of pressing too hard
« Reply #3 on: March 06, 2013, 02:45:25 PM »
Boofer--I think you've described, essentially, my reason for the question.  If, as you and I have both come to understand, that the moisture content is determined prior to pressing and that pressing does little to change that moisture content, then how hard I press shouldn't matter in that regard.  Pressing's affect on density might be a reason to use different pressures, but it seems to me that if you want the curd completely knit/closed, then the density is also largely set by the curd moisture level and not really dependent on the pressure used.  I can see applying a reduced pressure to leave an open structure--mechanical openings.  But unless that small amount of difference in whey expelled due to pressing makes a big difference in final cheese texture/flavor/etc, I'm not convinced it really matters.  If it appears I missed what you are saying, Boofer, please let me know.

Tiarella--thanks.  I think there was a recent discussion that suggested pressing and acidification don't really have much to do with each other.  I can see how applying a large pressure initially might expel some whey that, under a slower pressing regime, would still aid in acidification, though, i wonder if you still use a slow regime (going from lower to higher pressures), but you just keep going higher, will it make any difference?

Tom Turophile

  • Guest
Re: Consequences of pressing too hard
« Reply #4 on: March 06, 2013, 03:12:19 PM »
13 PSI????  I've been documenting all of the recipes that I have and hadn't come across that.  That's gonna be a lot of pulleys...

I don't get the use of cheesecloth on the top of the cheese when you have a perfectly good flat follower on top.  It has only caused me wrinkles.

Offline Tiarella

  • Old Cheese
  • *****
  • Location: Chester, MA, US
  • Posts: 1,748
  • Cheeses: 81
  • Default personal text
    • Farm Blog
Re: Consequences of pressing too hard
« Reply #5 on: March 06, 2013, 04:35:55 PM »
Tiarella--thanks.  I think there was a recent discussion that suggested pressing and acidification don't really have much to do with each other.  I can see how applying a large pressure initially might expel some whey that, under a slower pressing regime, would still aid in acidification, though, i wonder if you still use a slow regime (going from lower to higher pressures), but you just keep going higher, will it make any difference?

Mike,  do you have the book by Gianaclis Caldwell?  I think she talked about this in there.  I don't have time to look it up now but perhaps later during my "before evening chores cup of tea".   :-\

mjr522

  • Guest
Re: Consequences of pressing too hard
« Reply #6 on: March 06, 2013, 04:41:45 PM »
I do.  I looked it up last night before asking, though now I don't recall exactly what she said (and it's always possible even though I read it, I missed something).

Alpkäserei

  • Guest
Re: Consequences of pressing too hard
« Reply #7 on: March 06, 2013, 05:28:16 PM »
ok there is a difference in whey expelled from the curd while cooking and whey expelled from the cheese while pressing. it is true that once the cheese is pressed into a loaf, the curd does not expell whey, and pressing at normal ranges doesnt drive moisture from the curd.
when we remove the curd from the whey and put it into the form, there is a lot of 'free whey' that comes with it. this is trapped between curds, clinging on b y surface tension, etc. one of our goals in pressing is to drive this free moisture out. again, we are not driving moisture from the curd
the point of a good, long pressing is to get rid of this moisture that is not contained within the individual curds. if we dont, it will pool up and cause holes in the pressed cheese -these are what we refer to as mechanical holes. so we have to papply a lot of force to the cheese to drive the curds together and force this liquid out of the cheese. I prefer long time periods over heavy weight. I use to 8 to one press factor, which usaually will come out with very low psi compared to the amounts you all typically find in recipes. i dont have mechanical holes because i turn my cheeses 6 times and press for 20 hours
the free whey should have no effect whatsoever or culture activity within the curd once it is all in the press. here the only variable we can control that will affect acidification is temperature.
the energy of pressing is used to expell whey and to fuse the curds together. this action does generate a very small amount of heat inside of the cheese, but this is small enough not to really matter. most of the weight travels straight through the cheese and into the table. this means that above a certain point, adding more pressing weight doesnt really do anything for you.

mjr522

  • Guest
Re: Consequences of pressing too hard
« Reply #8 on: March 06, 2013, 05:36:30 PM »
Alp--makes sense.  Then, you would agree with the statement that too much pressure doesn't hurt?

Alpkäserei

  • Guest
Re: Consequences of pressing too hard
« Reply #9 on: March 06, 2013, 05:44:37 PM »
when you appply a force to a curd, it responds by applying an equal counter force in the opposite direction. this all gets pretty complicated within the structure of a cheese, but it is enough to say that for every pound of weight you apply to the cheese, it pushes back with the same amount of force. the curd contained within the confines of the form will not be compressed by this force. an easy way to demontrate this is to apply force to water in a container. the water does not change and if you could apply enough force to do so, the water would simply return to its natural density once this force is released. the same happens in our cheese. force will only serve to drive out free moisture as curd is packed together. you could make the case that excessive amounts of force could in fact trap whey inside, as the weight drives the curd structure together tight enough to preven the liquid from escaping.a more gentle force will apply the necessary compressive action to force the whey out wihthout driving the curd together hard enough to trap pockets deep inside. think of a rubber seal or an engine gasket. these seal by compression. you tighten them up to the point where liquid, air, etc cant get around the,m if you looses them up a bit, they leak. the same thing might be happening in your cheese. you tighten the curd up so much that it seals, and the whey cant leak out.

mjr522

  • Guest
Re: Consequences of pressing too hard
« Reply #10 on: March 06, 2013, 07:10:05 PM »
That all makes sense (I actually teach a class on statics and strength of material and will be teaching classes on fluid/thermodynamics).  The distinction you made earlier between expelling whey contained in individual curds and whey stuck between the surfaces of clumps of curds is a good distiction.  I can see how a rapid application of high levels of pressure might cause the curd to knit and trap some of this interstitial whey that would escape with a less severe pressing regime.

Offline Boofer

  • Old Cheese
  • *****
  • Location: Lakewood, Washington
  • Posts: 5,015
  • Cheeses: 344
  • Contemplating cheese
Re: Consequences of pressing too hard
« Reply #11 on: March 06, 2013, 07:29:07 PM »
But don't commercial creameries apply a lot of force to multiple cheese forms for a relatively short period of time?

-Boofer-
Let's ferment something!
Bread, beer, wine, cheese...it's all good.

mjr522

  • Guest
Re: Consequences of pressing too hard
« Reply #12 on: March 06, 2013, 07:51:40 PM »
I was under the impression that they do...

Sailor Con Queso

  • Guest
Re: Consequences of pressing too hard
« Reply #13 on: March 09, 2013, 02:34:17 PM »
I have watched traditional Parmesan makers in Italy use just a 10 pound weight on top of a 100# wheel, with no press at all. It's not just about the weight and pressure, it's about getting a good knit. There are lots of factors that come into play, and there are discussions throughout the Forum. As I have said before, I make 39 different kinds of cheese commercially. I usually press around 2 psi but I never press with more than about 3-4 psi. The only exception is Cantal, which I press around 6 psi.

John@PC

  • Guest
Re: Consequences of pressing too hard
« Reply #14 on: July 04, 2014, 03:26:53 PM »
I found this discussion looking for preferred pressing range and it contains very good information.  Someone mentioned Caldwell's book and from what I can find she avoids specific press weights / pressures and pretty much says as much as needed (a method I use now).  Karlin's book does have press weight but none more than 40 lb. on a 8" tomme.  Putting it all together would you say that 100 lb equiv. dead weight would be about the max you would need for up to 6" dia. mold (3.5 psi) or 8" dia. mold (2.0 psi)?  Reason I'm asking is I'm ready now to finishing commercialization of our compact press and wanted to make sure it's designed to provide a decent max weight / pressure.