Pounds of pressure - principles?

[Bernardsmith]

I can follow a recipe but what I would like to understand is not what pressure I need to apply to my rounds for what length of time but why specific weights are indicated in recipes for the lengths of time they are. What exactly is each level of pressure designed to do and why the specific length of time is the time that is cited. Presumably the weights and lengths of time are not determined by accident or trial and error so what are the principles that undergird each decision? Thanks

[wharris]

The pressure applied and its duration is designed to do a couple of things.
Primarily its designed to force curds to knit together into a single block while reducing the spaces inside the block.
Additionally, this forces excess whey from the curds.

Too much pressure and you break down the structure of the cheese, too little and you don't get a good knit.
The variances are due to the properties of the various cheese curds, and the desired outcome.
In either case, the actually pressure and duration values are the result of a heck of a lot practice and food science.

Good luck!

[Bernardsmith]

Ah, Thanks ... but are the principles easy to articulate or  are they so occult (hidden) that we simply have to depend on recipes?  - I ask because I come from a wine making brewing background and the key principles are all accessible and so if I know what fruit I want to ferment and know the sugar content of the fruit and its pH,  the ambient temperature of the room and the yeast I want to use I can develop a recipe based on principles that other wine makers can make good sense of and either applaud or critique. But with cheese  much of the information seems to be hidden so what we have access to are recipes - but recipes are merely  the outcomes of principles

[Gregore]

Problem with cheese making is that 20 things or more can effect the outcome quite a large amount , but .....

Simple principle of pressing is if molding at higher ph ( above 6 then curds will bond with little or know pressure , just time .  When molding well below that , pressure is needed to get the curds to bond . The lower the ph the more the pressure needed .

On curd that is low ph and salted ( cheddar) then lots of pressure is needed

Pressure effects the moisture only so much  , if I was to squeeze the crap out of a cam with the pressure of a cheddar then the curd would all squeeze out of the mold . Moist or dry curd is more a factor of cooking time temp. and agitation , next in line for moisture is low ph the lower the dryer and more crumbly the texture


what pressure can do is help get the moisture out from between  the curd interfaces

So now if you look at most recipes you will see that soft cheeses that are molded at high ph use very little pressure , cheese that are of a medium hardness like a tomme are molded at about 6.2 or so and need 8 pounds or so , and cheese that are much more dry are lower ph when pressed and thus need a whole lot more pressure.

i assume you ask becuase you would some day like to make a new cheese from snatch ? If so you need to decide the final cheeses qualities and then know the types of steps it takes to get to that general direction , from there only multiple times of creating and really good note taking  along with minor tweaking will get you right where you want to be.

Too wet do this this or this to change it , too dry do that , that or that plus a little of this .

And length of time  under pressure is used instead of stop at such and such ph ( just like baking for a set time in a recipe)  with a ph meter and know targets just do each step until know ph then move on to next step

1 other thing if all of that was not complicated enough  I think I read some where that  more pressure increases ph faster.

This is why I always recommend for beginners to make the same 2 or 3 cheeses over and over for the first year or so . How can one learn to control,the out come if you are alway changing paths ( recipe)  that is like learning to drive a car at world class level by  never driving the same car twice and never driving on the same track and never using the same tires . 

And almost as important it is even better if that cheese ripens sooner rather than later as it is hard to learn if you can not taste the outcome for a year.

Another option is to stick to a family of  similar cheeses  and as you make different recipes you will see what they have in common and what they don't and how that changes a cheese .

I know we all like to try new things but some of the most knowledgeable gurus on this forum all seem to have a go to favorite cheese that they make multiple times per year.

And after saying all of that it is all so complicated that  I feel I barely understand any of it ,

[Gregore]

 I should add that nothing is hidden it is just that it is really quite complicated and a good recipe is worth it weight in golden cheese as it will make it all seem so easy .

I have never made much alcohol but I suspect that cheese has more variables on a chemistry level than wine or beer by a factor of ten

[Fritz]

I have never made much alcohol but I suspect that cheese has more variables on a chemistry level than wine or beer by a factor of ten

..... Yes, but you won't care as much after a few glasses of dry crumbly wine 

[wharris]

As a fellow winemaker, I certainly understand the basis for your question.   
By default, we want to be told why, and how.  (as opposed to being told what to do.)

I can only say that there has been much science applied to the making of cheese. The results of which are available if one cares enough to go find it and then read it.

My only caution is that if you are not careful, you might just get what you ask for.
And you can find yourself staring at a food science report that can make your head spin, and leave you wishing for a simple answer.
(unless your name is linuxboy!)


I would look here for more details

[Bernardsmith]

Many thanks to every one who responded - Very useful information from everyone.
Gregore, I don't have the arrogance to imagine that my aim is to make a different cheese. Nothing like that. In fact Wayne just captured my frustration. My real question is the problem I have with recipes (of all kinds). I much prefer to know what outcomes I am looking for rather than simply what inputs I need to apply. If a recipe tells me to allow the curds to drain under their own weight for an hour what outcome is it that the recipe is designed to achieve. Does my cheese need to drain for 1 hour to achieve that outcome  - or does it need to drain overnight and into the next evening? Or does it need to drain only for 30 minutes? If a recipe advises me to increase weights from say 1 lb to 8 lbs to 24 to 50 at specific times what is it I should be looking for /measuring before I actually increase the load on the curds?

[awakephd]

Bernard,

The information above is good, but there is another way to approach this that might be helpful.

Always start with low pressure - just enough to begin to compact the curds together, let excess whey escape. After 30 minutes, increase the pressure - just to the point where whey is seeping out gradually. After 30 minutes, increase again, again looking for whey just seeping out. By that point, you will have a good idea whether or not the curds are going to take just a small amount to knit, or whether you're really going to have to ramp it up. The further along you get, the less you will see much of any whey coming out.

As soon as possible, start flipping the cheese each time you increase the pressure - I say it that way because, with something like a cheddar, it may still be way too crumbly to handle it the first time or even two.

A couple of other points: temperature of the curd makes a difference; warm curd knits more easily than cold curd.

And super-important: cheeses that go into the press before salting (e.g., tomme, gouda, asiago, parmesan, etc.) need to be monitored carefully so that they go into the brine (or start dry salting) at the proper pH. For most cheeses, that means around 5.3. In my experience, if I follow the typical recipe to let a Gouda stay in the press overnight, I don't wind up with Gouda; I wind up with something that has gotten far too acidic, and as a result the paste is crumbly rather than flexible, and the taste is sharper than it should be. Ideally, you control the pH curve so that the cheese has time to knit well by the time it reaches the target pH.

If you want the ultimate work-out, make a Cantal - the curd is pressed, unsalted, for 24 hours, allowing it to bottom out on pH; then it is milled and salted, and then it is pressed again - now cold and low pH. Takes a huge amount of psi to get a decent knit!

[Fritz]

Please keep in mind Bernardsmith, that most recipes are written for the masses. The authors deliberately keep the process simple and easy to follow. As Wayne said.. There is additional info out there, for those who seek it...

The average Cheesemaker here and those that buy cheese recipe books, usually appreciate the "simple" version. The most detailed book I own is "Mastering Artisan Cheesemaking" by Gianaclis Caldwell... It isn't a university course textbook ...but if you read that one cover-to-cover... You will surely have most of your questions answered and be a smart cookie...

Have YOU read that one ...cover-to-cover?

F

[Bernardsmith]

Not cover to cover but I use the book as one of three I have open each time I try to make a different cheese (tonight, an Emmenthal)

[Bernardsmith]

Bernard,

The information above is good, but there is another way to approach this that might be helpful.

Always start with low pressure - just enough to begin to compact the curds together, let excess whey escape. After 30 minutes, increase the pressure - just to the point where whey is seeping out gradually. After 30 minutes, increase again, again looking for whey just seeping out. By that point, you will have a good idea whether or not the curds are going to take just a small amount to knit, or whether you're really going to have to ramp it up. The further along you get, the less you will see much of any whey coming out.

As soon as possible, start flipping the cheese each time you increase the pressure - I say it that way because, with something like a cheddar, it may still be way too crumbly to handle it the first time or even two.

A couple of other points: temperature of the curd makes a difference; warm curd knits more easily than cold curd.

And super-important: cheeses that go into the press before salting (e.g., tomme, gouda, asiago, parmesan, etc.) need to be monitored carefully so that they go into the brine (or start dry salting) at the proper pH. For most cheeses, that means around 5.3. In my experience, if I follow the typical recipe to let a Gouda stay in the press overnight, I don't wind up with Gouda; I wind up with something that has gotten far too acidic, and as a result the paste is crumbly rather than flexible, and the taste is sharper than it should be. Ideally, you control the pH curve so that the cheese has time to knit well by the time it reaches the target pH.

If you want the ultimate work-out, make a Cantal - the curd is pressed, unsalted, for 24 hours, allowing it to bottom out on pH; then it is milled and salted, and then it is pressed again - now cold and low pH. Takes a huge amount of psi to get a decent knit!

Andy - This is very much what I am looking for - key data (like the pH I want to reach, the amount of whey I want to expel ). Thanks.

[Gregore]

One thing I can recommend is .....

  When you are waiting for the cheese to do its thing is a great time to read that particular section of the Caldwell book .

Eg while waiting for the rennet to be added read the rennet section .

[Bernardsmith]

Thanks Gregore, And I do... but here's my difficulty: Last night I began to make my first Alpine cheese - an Emmenthal. I see that Caldwell (pps 277-278 ) refers to target pH's and I like that. But when it comes to salting she talks about aiming for a target salt content (of the cheese at around 1.1- 1.2 % because a larger percentage of salt (in the cheese) will inhibit the activity of the propionic bacteria. OK. but she does not advise her readers on the actual concentration of the brine. She says it should be a "heavy brine". Is that 20%? , 25% more? less? I don't know but I made a 25% solution using some of the whey that was expelled from the curds. How long to brine? Well, Caldwell suggests 2.5 hours for each pound. OK... but I also have open Ricki Carroll's book and for a similar cheese she implies a 25 % brine solution (see p122) but that the cheese should be brined for 12 hours - (no matter that she refers to a cheese that should be about half the weight of Caldwell's. So how are we to make sense of the chemistry that undergirds these recipes? For one cheese maker 2 lbs of cheese should be immersed for about 5 hours in order not to create a cheese with more than about 1.2 % salt and for the other 12 hours of soaking won't create any problem. Sure , I can experiment and make multiple batches and see which advice about brining I prefer... but 5 hours is not 12, is it? Or is it the same when it comes to cheese making? Or is there a simple way of measuring the salt content of the cheese? 

[Gregore]

I almost always salt by weight and percentage unless I am feeling rather lazy then I brine . I would rather have the right amount of salt in my cheese than like you point out "guess" at the right timing .

Add a little bit extra salt as some it washes away  as the cheese weeps whey when it is salted

Eg. On a reblochon I will add 1.8% instead of the called for 1.5%  I rub it in every where .


Found the following in one of my books

This is minimums and max  on salt for the following cheese

Swiss   -  min. .04 to max 0.6
Tomme - min 1.4 to max 2.0
Reblochon - min. 1.3 to max 1.5
Camembert - min. 1.2 to max 1.7
Roquefort - min 3.0 to max 3.6

My pet peeve about recipes is when they do not include ph markers , but thankfully I can usually piece them together from a multitude of recipes .