Press horizontally or vertically?

[Boofer]

I recently picked up four small Kadova moulds. I am anticipating filling and pressing them.

My question is:

• Is it more effective to have them all on the same horizontal plane and press them all with a spreader board on top?
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or. . .

• Should I stack them one on top of the other, vertically, and press the very top mould?
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I'm curious what is the most conventional and effective method. I think I've seen both forms used. The moulds are grooved and designed for stacking so that kind of makes sense. If I went that route, I might have to put them in a PVC "sleeve" to ensure they maintain their vertical alignment. Seems like I read a thread on that here recently.

-Boofer-

[MarkShelton]

Here's my thoughts:

With all the molds on one plane, you would need 4X the pressure since it is being distributed evenly across 4X the surface of one cheese, however, all the cheeses will be pressed equally.

With the molds stacked vertically, the pressure wouldn't be spread out, so the pressure for pressing one cheese will work on them all, but the one on the bottom will have the press load plus the weight of 3 more cheeses and molds than the one on the top. I suppose this can be remedied by changing the order of the cheeses when they are flipped.

I suppose it's up to you and your press capacity. What kind of press do you have?

Here's another thought. I don't know if your press can accomodate this suggestion, but what if instead of vertically, you aligned the molds top to bottom in a horizontal fashion and pressed horizontally?
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I think it would really only be possible with a pneumatic press and the only advantage would be that you wouldn't have to change up the order of the cheeses. Probably not very feasable, but just another variation.

[Sailor Con Queso]

Mark is right. If you spread them out you will need 4 times the weight to acheive the same pressure.

Pressure is a constant, weight is not.

[sominus]

Another thing to consider is the stability of the stack.  You could easily stack 2 tall (and two wide) without inducing a "wobble" to the mix.  However, stacking 4 high would add a certain lateral instability (due to a number of factors, not the least of which being an unpredictably "mushy" cheese that may not press evenly) that could end in a messy disaster when you're not looking.

My monster press is still in the tweaking phase, but even a small instability/deflection in the direction of force caused a hoop to move and produced a lop-sided cheese quite quickly.  Fortunately I was able to re-press it and level it out.

The idea of a strictly lateral press is interesting...  Draining would be the problem there, but it could easily be done with a couple pulleys and the right lever setup.  Also a problem would be centering and "aiming" the force appropriately.


Ooooo... physics!

-Michael

[Boofer]

Downward pressure is the operative mode of the press I'm building. Pressing from the side is not an option.

Don't the commercial cheeseries worry about excessive pressure on the bottom mould when they stack them?

In another thread I posted my worksheet which tries to project expected psi for a given applied weight. I've massaged and corrected the spreadsheet, incorporating figures for the four small Kadova moulds. The calculations are based on the four moulds being pressed equally with a spreader board.

If I were to press them all stacked one on top of the other, I would secure them vertically by enclosing them in a PVC tube. This would prevent any "lateral instability".

-Boofer-

[padams]

Sailor, and any one else who can explain this.....How is weight not a constant with a direct pressure press?  I understand that if the cheeses were spread horizontally, then 4x the weight would be needed.....but if I stack 50lbs on top of my cheese mold, how can it vary?  It's always going to be 50lbs.  The density of the cheese will change, but it will still be 50lbs, whether it's been 1 hour or 12 hours.  Or is that how it works...because of the density of the cheese at different points during pressing?

[BigCheese]

I have wondered about stacked pressing as well. There is a video somewhere around here with large kadovas being pressed in A frame style, and I was wondering how they manage the difference in weight. I saw some cool pictures on FXcuisine.com of lateral pressing, it really seems cool and ideal in many ways.

[MarkShelton]

@padams: Weight CAN be a constant if everything else is constant. Say you have a 4" mold and a 50# dumbell as a weight. Whenever you put the weight on the mold, there will be 50# of weight on it, simple enough. However, if you change to a 6" mold, that 50# is still 50#, but the effect it has on the cheese is much different. The pressure that 50# exerts on the larger mold is much less since there is the weight is spread out over more area.

If you have a pneumatic press and use 2 psi, then whether you use a 4" or 6" mold, there will always be 2# per square inch, and the cheeses will be pressed the same no matter how big the mold is.

If you have a spring press, it is a little trickier. Say you have a 3" spring that exerts 50# (or it takes 50# to compress the spring, same thing) and you compress it fully to press your cheese. Initially it has 50# of pressure, but as the cheese is compressed, the spring is de-compressed. When the spring is only half compressed, you're only getting 25#. If the cheese compresses a full 3", then you are no longer pressing because there spring is no longer exerting any force at all.
Spring presses are like the dead weight also, in that if the weight is distributed over a larger area, the effective pressure on the cheese is less.

[padams]

Thank you, Mark!  Only one more question....is a 4in hoop the constant? (vs. 6 or   I know I saw the formula for figuring that out somewhere.....

[Sailor Con Queso]

Let's assume that you are using a 4" hoop and you press your Goudas with 25 pounds. That works out to 2 pounds for every square inch of the follower - psi (I press my Goudas at 2-3 psi). If you are getting good results, great then you stick with the same mold and weight - EVERYTHING is constant in this scenario.

However, like most of us, you decide you want to make bigger cheeses, so you move up to a 6" hoop. If you use that same 25 pound weight to press your Goudas in the bigger hoop, your results will be inadequate. That same 25 pound weight is spread out over a larger surface area so the pressure (psi) on each square inch of the follower is MUCH less. So the Gouda will not be pressed as well and may have mechanical holes. To compensate, you have to add more weight to achieve the same results (psi). How much more? Well I posted a psi table in a couple of other threads, but it works out to about 60 pounds to achieve the same 2 psi. So, the hoop has changed, the weight has changed, but the pressure (2 psi) has remained constant.

Here's another way to look at it. When you put air in your car tires, you use a little gizmo to measure pressure - usually somewhere around 35 psi. Now think about inflating one of those 6 foot tall monster truck tires. If you want the same "feel" to the tire, you would inflate it to the same 35 psi, but it would take a LOT more air to achieve the same pressure.

[padams]

So, are recipes assuming a 4in mold?  Sorry, I have to try to wrap my head around this (there is a reason I failed algebra in high school).

The analogy was great, Sailor.

[BigCheese]

Sailor, I have been looking for your guide to determining psi. Could you just tell me a search string that will help me find it? Thanks in advance.

[Sailor Con Queso]

Here it is again.

Just find the diameter of the hoop/follower at the top. Then follow that column down until you find the PSI that you want. Then in the left column it tells you what weight you need to acheive that PSI.

For example - I am pressing a Pyrenees right now in a 7 inch mold with 150 pounds. That is 3.9 PSI.

[Boofer]

The picture is the model I was following for my press. It shows the spreader idea. It wouldn't seem that the pressure applied is very great considering the size of those Kadova moulds and the fact that several are being pressed with the same applied pressure. I believe that the setup is a 2-pulley with a four-foot (1.5 meter?) lever.

As of today my press is almost complete except for the follower head. I am anxious to test it to validate or invalidate my grand cheese pressing ideas.

-Boofer-

[MarkShelton]

@padams: if all you use is a 4" mold, then it would be a constant. Otherwise, it joins the list of variables.

What I think you're asking, though, is if recipes that call for pressures in pounds (as opposed to psi) are intended to be made with 4" molds... right? If so, then I think so, at least the ones by Carroll and Smith. So if a recipe calls for 50#, and you are using a 6" mold, then you will need to increase weight applied to ~112# to compensate for the distribution/dissipation of the pressure.