Author Topic: PH in cheddar making.  (Read 23248 times)

vogironface

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PH in cheddar making.
« on: November 15, 2009, 03:53:38 PM »
Yesterday I finished a batch of cheddar.  I used the cheddaring method of preparing the curds.  I have been trying to learn from some of the threads here about PH readings during the process.  Not having a PH meter I used litmus paper from my local home brew store.  This is terribly inaccurate, but the best I could do.  I suspect that the acid dropped to low, but your thoughts would be appreciated.

PH at the end of cooking was 6.2
PH after curd was drained and just before cheddaring was 6
PH just before milling was 5.2
PH after removing from the hoop was 5, though this reading is nearing the lower edge of the paper I used so it may not be right.

What is the most critical reading, is it the PH just before salting?
Also, at what PH does the cheese become dry and crumbly?

As an aside, I was amazed how quickly the ph dropped once it started to move.  I think you really have to watch it closely.  Some of Wayne's posts would indicate as much as well.

Thanks everyone.

Offline DeejayDebi

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Re: PH in cheddar making.
« Reply #1 on: November 15, 2009, 06:09:37 PM »
I don't use a pH meter as often as I should. It seems to me the most critical step has been the acid development level before draining the whey to ensure good moisture and texture. Other steps can be corrected for but once the whey is removed there's no room for correction.

linuxboy

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Re: PH in cheddar making.
« Reply #2 on: November 16, 2009, 02:15:47 AM »
two two most critical issues are pH at drain and pH at salting for cheddar, and actually, for most cheeses. Draining pH should be 6.0- 6.1 for cheddar. Yours was too  low, that means texture will be more crumbly. Second pH at salting should be 5.4-5.5.  5.6 is on the high range, typically the target is right at 5.4. It really makes a big difference to be even .1 off.

dry and crumbly cheese can be the result of multiple aspects. ph at whey drain is the big one. Overworking the curd, amount of rennet, ph at salting, ambient room temp, psi of press also all play a role.
« Last Edit: July 28, 2010, 08:10:44 PM by linuxboy »

FarmerJd

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Re: PH in cheddar making.
« Reply #3 on: November 16, 2009, 05:18:11 AM »
2 questions:
What exactly is overworking the curd?
What effect does the manner and timing of salting have? I mean that if I hit the target ph of 5.4 (this is in the whey not curd, right?) at the end of cheddaring, and I begin salting, is there a lot of variation depending on how I salt? e.g. 3 rounds of adding salt at ten minute increments, 1 big dump of salt and then mix, or other approaches.

I was making jack this past week using my new ph meter and was at the point right before adding cold water to drop the temp after cooking the curd. The ph finally was 6.21 and I started draining the curd and I decided to monitor the ph while I was draining and the bottom just fell out. I was at 5.8 before I could get the whey down to the curd and start adding water. I was not expecting that kind of rapid change either. Are the points that linuxboy pointed out as the most critical also the most difficult to manage? It seems that I need a quicker method of whey draining.

vogironface

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Re: PH in cheddar making.
« Reply #4 on: November 16, 2009, 05:47:52 AM »
Farmer,

I have the same questions but here are my thoughts.  I know when I stir the curd to much to early they seem to break apart and release fat into the whey.  Perhaps this is what linuxboy meant. 

If you notice the ph dropping so rapidly every time then perhaps you could begin to remove whey sooner so you hit the target.  Could that work or is there not enough change in PH before the drop off to time it right?

Linuxboy, Thanks for the info.  I have 1 to add to your list.  What effect does the room temp have on the cheese with respect to it being crumbly.  I placed my press in the oven with the light on since it snowed here that day.  I was afraid it would not knit together.  The result was the first 4 hours of the pressing was at about 80 degrees as was the cheddaring.  Any idea what this means to the cheese?

linuxboy

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Re: PH in cheddar making.
« Reply #5 on: November 16, 2009, 04:16:54 PM »
2 questions:
What exactly is overworking the curd?
What effect does the manner and timing of salting have? I mean that if I hit the target ph of 5.4 (this is in the whey not curd, right?) at the end of cheddaring, and I begin salting, is there a lot of variation depending on how I salt? e.g. 3 rounds of adding salt at ten minute increments, 1 big dump of salt and then mix, or other approaches.

I was making jack this past week using my new ph meter and was at the point right before adding cold water to drop the temp after cooking the curd. The ph finally was 6.21 and I started draining the curd and I decided to monitor the ph while I was draining and the bottom just fell out. I was at 5.8 before I could get the whey down to the curd and start adding water. I was not expecting that kind of rapid change either. Are the points that linuxboy pointed out as the most critical also the most difficult to manage? It seems that I need a quicker method of whey draining.

Overworking the curd causes curd shattering. You experienced this when your ice cream mixer was going at too many RPMs. Like Ben said, fat is released and you will get a dryer cheese. Healing curd before stirring helps to minimize shattering.

Manner and timing of salting has to do with hitting a final salt content in the cheese. For example, if you dump all the salt in at once, it will help the curds expel more whey. Well, all that whey will wash away some of the salt and the final internal salt percentage will be less than if you salted at 5-10 min increments. Commercially, incremental saltging is most often used for practical reasons. The curds need to be coated evenly, so a third or half the salt is spread out on top, the curds are tossed with a large pitchfork, which takes 5-10 mins, and then more salt is added. For home application, I suggest the same approach. You want even salt coverage in at least two applications. Let the whey drain after salting, pour it out, toss the curds, and add more salt.

Yes, target pH is of whey at the closest point possible to the curd. Meaning whatever liquid the curd expels. You couldn't accurately measure actual curd ph, anyway. To do that, you'd need to pulverize the curd and use an emulsifier, then measure. If you press the pH meter to the curd, you'd be testing the pH of the whey that the curd expels, vs the whey in the pot. There is a slight difference in that the whey leftover acidifies faster than in the curd.

The interesting pH behavior you experienced with the jack most likely has to do with the water addition or the acidification rate of your starter. Milk has a lot of buffers in it. If you add water, the buffer capacity may be decreased as ions come out of solution (this is less likely), leading to a faster drop. Another possibility is that your starter acidifies faster after it hits a pH of 6 (this is most likely). The way you figure this out is to look at the acidification curves. If you don't have one from your supplier, ask for it, or make one yourself by plotting pH vs time in a cheese. If for a normal, non-washed cheese the acidification is more steady, then you know it was the water that led to the drop.

Just another quick note... you could drain whey earlier than 6.2, but in most cases, it is impossible unless you make the curd very small and heat up quickly. By the time you can drain whey, the pH will likely be 6.1-6.2. If it's less than that, use less starter next time, and hurry up and finish draining :)

Ben, ambient room temp influences knitting in the mold and acidification post drain. Of these, the knitting or lack of it contributes to crumbliness. If the temp is lower, you need more weight or to press for longer for the curds to knit. If your curd was at 80 degrees for knitting and cheddaring, you're doing well. Commercially, the vats are heated while cheddaring takes place.

Ideally for most styles, what you want is to knit the curds well together right away (that initial hour while the curds are hot is crucial) but without using too much weight or the water content will not be the same throughout the cheese, then let the cheese sit for a bit so the remaining lactose can be digested. If there's too much lactose, other bacteria can eat it and the cheese has less preserving capacity.

Phew. long post.



« Last Edit: May 26, 2010, 11:45:24 PM by linuxboy »

FarmerJd

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Re: PH in cheddar making.
« Reply #6 on: November 16, 2009, 04:58:25 PM »
Thanks. Light is beginning to come on.

Likesspace

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Re: PH in cheddar making.
« Reply #7 on: November 17, 2009, 01:39:27 AM »
Sheesh Linuxboy!
Just when I thought I was getting a handle on cheddar making you hit me with this!  :)
I was perfectly fine until I read that even .1 ph can make a big difference in the outcome of a cheese. That's sort of intimidating.
Even though I now have to re-think everything I'm doing I DO appreciate the information and your thoughtful posts. The amount of information you have is amazing and the fact that you share it is appreciated.

Dave

wharris

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Re: PH in cheddar making.
« Reply #8 on: November 17, 2009, 01:45:22 AM »
I was perfectly fine until I read that even .1 ph can make a big difference in the outcome of a cheese. That's sort of intimidating.

This is why I consistantly say that a pH meter is essential for cheese generally, and cheddar specifically.

Offline DeejayDebi

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Re: PH in cheddar making.
« Reply #9 on: November 17, 2009, 01:48:42 AM »
Great info Linux!

Likesspace

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Re: PH in cheddar making.
« Reply #10 on: November 17, 2009, 02:10:09 AM »
I'm with you Wayne. I didn't realize this for the first 3 years of making cheese but now I would not even attempt a cheddar without one.
Case in point...
Two weeks ago I made a stirred cheddar and was having some serious problems with my meter. I could not get it to stay calibrated and basically ended up going only by recipe times.....
Well since this was a cheese that was made to refine a recipe I opened it this past weekend and it was a pitiful cheese.
The texture was crumbly, open and slightly bitter. I was going to toss it but my wife reminded me that my dad will eat ANY cheese so instead I guess I'll take it to him to try. I just want it out of the house because it ticks me off when I see it.
On the other hand, a week ago I made another attempt at a stirred cheddar. This time I had my meter calibrated correctly (used new solution and re-calibrated mid make), and I also cut this one open this past weekend.
With this cheese I was able to take a very thin slice off of the wedge and could actually fold it completely in half without it breaking.
Of course the taste was pretty much non existent but it had a good mouth feel, although a bit dry for my liking. Thanks to Linuxboy I know that this dryness was due to cooking the curd too quickly so I knew what to do differently on my next batch to make it better.
Well this past weekend I made a new stirred cheddar and hit all of my Ph and cook marks perfectly. In fact I've never had a cheese go any better than this one.
Once again I will cut this one open in a week or two to see what I have.
If I am satisfied (as I was on my last wheel) I will vacuum bag the other wedges and continue aging. I also raised the press pressure a bit to try to get a more closed curd, although after reading the above I probably should have done this earlier in the process than I did.
I've decided that cheddar is the cheese of this season.
It's fun to make and the rewards are high if made correctly.
Besides, I'm already sick of trying to perfect swiss and I haven't even tried one yet this year. :)
There's no doubt that other cheeses will be made this year but cheddar is my focus and it's posts like the above that will help me along the way.

Dave

linuxboy

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Re: PH in cheddar making.
« Reply #11 on: November 17, 2009, 02:17:43 AM »
Dave, the real truth of why pH is important is even more complex than that. pH or TA is a pointer to what's going on under the surface. The reality is that after the initial curd set because of rennet, there are complex reactions being carried out both at the cell level by bacteria and at a physico-chemical level in the whey and curd. The direct consequence of this is the amount of calcium and phosphate salts and lactose in the whey and in the curd. The whey drainage pH is an easy to measure indicator of the relative loss of lactose, and more importantly the stage of calcium phosphate loss and di to monocalcium paracaseinate conversion.

The level of lactose in the curds determines how much food bacteria have left before they give up and enter a more dormant phase of not replicating but just eating and staying alive. This is important for processes like cheddaring. And the level of calcium, phosphate, and paracaseinate conversion determine a number of things. One, it determines the rate of protein to protein interaction. Or more simply put, how well curds knit together and if they form a more open curd or closed curd (less calcium will produce a more closed curd, all other things being equal). Two, it in part determines the ability of the final cheese to melt and stretch. Three, it determines the moisture "feel"... that is less calcium will feel more "wet", say, like a havarti vs a swiss. Swiss has more calcium, and of course higher whey drain pH.

So it's not exactly 100% correct that a .1 pH difference will make a drastic change. All other things being equal, it usually does, most of the time. :D The important principle here is that the pH change is pointing to the rate of acid production AND how that acid production is affecting the natural buffering properties of milk (namely calcium/phosphate) AND how these two factors are related to the temperature, which influences acid production and rate of whey syneresis, AND the size of the curd/flocculation multiplier.

Oh and interestingly enough, higher calcium cheeses age better.

If you take careful notes and post them alongside the final cheese taste notes, I can usually help you troubleshoot what you can do to achieve a specific cheese profile.

Artisan cheesemaking to me is knowing a few details about the why of what's happening, and then remembering to carefully put them aside and practice the art. There are just so many variables that unless you have real-time monitoring during the make and analysis/standardization of the milk, producing a consistent cheese is a real challenge and art. And if you do standardize the milk and monitor everything, well, that's no fun.

[edit] my brain went faster than my typing, fixed.[/edit]
« Last Edit: November 17, 2009, 02:30:38 AM by linuxboy »

Likesspace

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Re: PH in cheddar making.
« Reply #12 on: November 17, 2009, 02:35:23 AM »
Okay, my head just exploded. I thought I had it for one shining moment and then... BOOM! Total mental overload.
Honestly, I figured out quite some time ago that it's the little things that make a big difference in cheese making. Having said that, I'm just now beginning to understand just how much is involved in turning out a quality cheese.
The way I see it, I will still be learning as long as I continue with this hobby (art form) so in my opinion it would be hard to find something that's more challenging and satisfying. In other words, making cheese is right up my alley.
Thanks again for all of the information.

Dave

Offline DeejayDebi

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Re: PH in cheddar making.
« Reply #13 on: November 17, 2009, 02:37:12 AM »
With all the cheeses, milk, cutlures, times, temperture combinations etc it will always be a learning experience.

FarmerJd

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Re: PH in cheddar making.
« Reply #14 on: November 17, 2009, 03:25:25 AM »
Since the subject is cheddar ph, I might as well add this quandry to this thread: I made cheddar today and forgot to add rennet to the water, added the water waited 30min and realized no curd was forming, then realized my idiot self never added the rennet, so quickly added rennet. This basically meant 30 extra minutes of culturing time added to the hour already passed. I plowed ahead and then at the end of raising the temp to 102 the ph was already down to 6.0. I figured this was because of the extra time with culture. Soooo..... Do I cook another 45 min now per recipe so that the curds develop properly or just drain now since I already passed the 6.1-6.2 and another 45 min would mean moving even further? went with experience and cooked until curds felt right; about 30 more min. Drained very fast;faster than ever. ph was 5.89. began cheddaring and only cheddared about 1 hr and whey ph was 5.29. Stopped and milled curd quickly and salted for about 10min then began pressing.

Ok did i completely blow it? Is this cheese a disaster? Should I have stayed with recipe or are the ph values the most important factor for producing a decent cheese?