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CHEESE TYPE BOARDS (for Cheese Lovers and Cheese Makers) => RENNET COAGULATED - Hard Cheddared (Normally Stacked & Milled) => Topic started by: Devon on May 31, 2012, 07:42:09 PM

Title: sudden drop in PH
Post by: Devon on May 31, 2012, 07:42:09 PM
Lately while making cheddar the PH drop is normal up to the cheddaring phase. Then the Ph drops very rapidly to the point I have to salt and press early. I have even tried raising the temp during cheddaring and stacking at a lower level for more heat transfer to expel more whey. Can anyone give any insight as to why the sudden drop in PH at this stage?
Title: Re: sudden drop in PH
Post by: Sailor Con Queso on June 01, 2012, 08:34:10 AM
Acidity is a logarithmic not a linear progression because bacteria theoretically double their population every 20 minutes. Every bacteria has a pH curve that predicts the rate of acid production, and for the first 2-3 hours (or more), there are not gigantic drops in pH. Depending on the cheese, the bacteria used, and the amount of starter used, that bacterial population and associated acid production "kicks in" from 3 to 5 hours into a make. You have complete control over over acidity at various steps along the way and may have to pitch, salt, and press when the cheese is ready, not because a recipe dictates a certain time.
Title: Re: sudden drop in PH
Post by: Boofer on June 01, 2012, 11:33:45 AM
Acidity is a logarithmic not a linear progression because bacteria theoretically double their population every 20 minutes. Every bacteria has a pH curve that predicts the rate of acid production, and for the first 2-3 hours (or more), there are not gigantic drops in pH. Depending on the cheese, the bacteria used, and the amount of starter used, that bacterial population and associated acid production "kicks in" from 3 to 5 hours into a make. You have complete control over over acidity at various steps along the way and may have to pitch, salt, and press when the cheese is ready, not because a recipe dictates a certain time.
This is good stuff. In the beginning, it took me a while for my mind to move from the dictates of a recipe with set times for ripening, renneting, pressing, etc., to an understanding of exactly what you're saying. I had to learn (and am still learning) what the milk was doing through the different stages. I always felt something was drastically wrong with my make if I didn't follow the recipe and do everything within the recipe's margins. The pH meter made me focus more on the actual progress within the milk. If it wasn't moving, neither was I. Why move to the next stage if the milk isn't ready? Conversely, if the milk seems like a runaway freight train, I'd better get on-board or I'll be left behind. That means my schedule is accelerated. Monitoring the pressing pH may mean stopping the press and moving to the brining phase to curb the bacteria's excitement and arrest the acidity development.

-Boofer-
Title: Re: sudden drop in PH
Post by: linuxboy on June 01, 2012, 02:33:51 PM
That's not a sudden drop. That is a normal drop for many types and strains of bacteria.

Here's what you have to remember about milk. It buffers. It's not like even with the non-linear way that pH works, and the bacterial mix and the way bacteriology works, you can have some clearly predictable outcome. Milk is a variable medium in which to practice your art. if you are skilled, you don't need a pH meter, because you can rely on intuitive and organic observations of milk and curd behavior. For the rest of us mere mortals, pH meters/titrators are a Godsend.

If you want to drag out the curve, use less culture, or switch culture to a slower blend, or regulate temperature to better coincide with the time and moisture parameters.
Title: Re: sudden drop in PH
Post by: NimbinValley on June 02, 2012, 02:23:56 AM
I have had a similar experience to you Devon.

Now that I am more aware of renetting pH I am finding that I may have to accelerate my makes also.  I was making a Blue last week and didn't rennet until 6.45 ( which took nearly 120mins of ripening to achieve) but then the rest of the make was very quick to achieve my whey off pH of 6.2.  I actually overshot it considerable so I will use less culture next time and stir a bit faster.  I am hoping that Blues will be a bit more forgiving with the extra acid developed.

Any comments will be appreciated.

NVD.
Title: Re: sudden drop in PH
Post by: Devon on June 02, 2012, 05:57:30 PM
Thanks for the input everyone. I decided to try again today making a cheddar with a few adjustments.

8 gals raw milk PH 6.72 heated to 88 degrees F
Added 1/4 teaspoon MA 011 (down from 3/4 tsp used in prior makes)
Held at 88 degrees F for 40 minutes PH 6.69
Added 1 teaspoon liquid animal single strength, floc in 15 minutes
Cut at 45 minutes into 1/2 inch cubes PH 6.57 rest for 5 minutes
Raise temp to 102 degrees F over 55 minutes PH 6.48
Held for 40 minutes PH 6.35
Drained and cheddared for 50 minutes PH 5.62
Salted (7 tablespoons) and pressed at PH 5.62 due to past sudden PH drop

It has been in the press for approximately 5 hours, is fairly dry already and the PH is at 5.30 (Updated Post) at 8 hours in and PH is 5.16, decided to remove from press to begin drying and actual PH taken from cheese is 4.94, it appears to still be dropping. (Updated Post) Final PH in the cheese this morning is 4.88 When does the PH stop dropping? This is the same problem I have been having lately where the PH drops into the range of 4.8 or lower during pressing and/or during drying.
Title: Re: sudden drop in PH
Post by: linuxboy on June 04, 2012, 08:53:16 AM
This looks like a decent make. Your native bacteria seem to be causing the acidification because MA11 shouldn't do that. Focus on your drain and your salt pH and the rest will take care of itself.

Title: Re: sudden drop in PH
Post by: Devon on June 04, 2012, 04:15:05 PM
So does that mean I should be draining and salting at a higher PH? If so what range should I be targeting for draining? Would it help to reduce ma11 starter from 1/4  to 1/8 teaspoon or leave out the starter completely? Every make ends up with a finial PH around 4.8 to 4.9, I want to target a finial PH of 5.2 to 5.3. I guess I am not understanding how to meet this target PH on the completed cheese, when it goes in the press, I no longer have any control over the PH drop.
Title: Re: sudden drop in PH
Post by: FRANCOIS on June 04, 2012, 05:02:39 PM
What Linux means is:
1.  Add more salt (slows the pH curve)
2.  Increase the pH you salt at. (shift your make up the pH curve)
3.  Monitor the pH and when it hits your target immediately put it in the chilelr to arrest the pH drop.

Any, all or one of these can get you to the final pH marker you want.
Title: Re: sudden drop in PH
Post by: Devon on June 04, 2012, 06:05:52 PM

If I add anymore salt the cheese will not be eatable, the salt does not appear to be slowing down the PH drop as shown in the make during pressing. I am already salting around 5.6 to 5.8. Which part of the make do I slow down on to be able to salt earlier? The only place I see is the ripening phase at the beginning.

Even removing from the press and putting in the refrigerator after 5 hours at a PH of 5.62 as in the make before this one, the PH still dropped to 4.82 by morning.
Title: Re: sudden drop in PH
Post by: FRANCOIS on June 04, 2012, 06:25:43 PM
It sounds like indigenous culture is dictating your pH curve.  You'll have to pasteurise, or a t least thermise, if all else fails.
Title: Re: sudden drop in PH
Post by: Sailor Con Queso on June 04, 2012, 06:40:37 PM
Devon,

With raw milk, you should always reduce your starter by 25% or more. As LB suggested, I would salt at 6.0.

You can also do a partial wash of the curds. Gouda washes about 1/3 of the whey. I would shoot for 10-15% whey removal. You will have to experiment with the wash temperature, but I would wash to within a few degrees less than target temp and then bring the curds up as you would normally. This will remove some of the lactose, slow the bacteria down, and help prevent your cheese from becoming too acidic.

Title: Re: sudden drop in PH
Post by: Devon on June 04, 2012, 07:07:17 PM
Sailor,

I did reduce the starter only using 1/4 teaspoon for 8 gallons, I think I will reduce it to 1/8 teaspoon. I will try your target PH of 6 then salt. I will make again this weekend. I have @ 8 – 4 lb wheels, each with the make schedule adjusted and the end result is still a ph of 4.8 to 4.9 that I guess will get trashed.

I really do not want to pasteurize unless I have to, kind of defeats the use of raw milk
Title: Re: sudden drop in PH
Post by: NimbinValley on June 04, 2012, 07:17:13 PM
I may be speaking out of turn here but if by 'trashed' you mean throw away then I would reconsider.  They should still be edible and may be really quite nice, not just like true cheddars.  If you were hoping to sell them then change the name  - I call mine "Oops".  The only problem is that people come back wanting to buy more 'oops'!

NVD.
Title: Re: sudden drop in PH
Post by: FRANCOIS on June 04, 2012, 07:31:49 PM
Washing could have a very signifcant impact on final flavour and texture (not in a good way), so be careful.  Salting
Title: Re: sudden drop in PH
Post by: linuxboy on June 04, 2012, 07:45:32 PM
wash can work, depends on the milk and make. But overall, if salting and hitting your pH markers for rennet, drain, and mill/salt are not doing it, AND if a cold crash isn't doing it either, then you have some oddity in the bacterial payload. Perhaps your native LAB are having a synergistic reaction with your starter to rapidly accelerate pH curve or do a too-low terminal. IMHO, if nothing else is working at all, including pasteurization, then call it a quirk of the milk and flora and live with it.  a 4.9 finish for cheddar is not the end of the world if you hit the drain and salt pH.

edit: I would try different starters before doing that, though.
Title: Re: sudden drop in PH
Post by: Devon on June 04, 2012, 08:09:23 PM
I will change the starter this weekend as well, I have been using Ma11,  I have on hand Ma16, FD and Meso 2. I have not tried pasteurization yet. I will split the 8 gals into two makes and alter each make and see what happens.
Title: Re: sudden drop in PH
Post by: linuxboy on June 04, 2012, 08:12:26 PM
Suggest until you dial this in to exactly how you want it, to use smaller batch sizes (1 gal, maybe 2) altering one variable at a time until it all flows, and take careful notes. It's part of product R&D, sometimes stuff just doesn't work as expected and needs tweaks. Of course if your molds and other equipment don't allow for it, moot point.
Title: Re: sudden drop in PH
Post by: Devon on June 04, 2012, 08:19:03 PM
All my hoops for hard cheese are 8 1/4 inch round by 7 inches in height and my press is set to these molds. I have been making cheddar for several years and made at least a hundred wheels. I have never experienced this before, salt always slowed or stopped the PH drop. I may also try 1 gal raw and 3 gal store brand milk. What do you think the outcome would be if I did not use any starter, would the natural milk have enough to do the job?
Title: Re: sudden drop in PH
Post by: linuxboy on June 04, 2012, 08:20:50 PM
it might. If you heated and left the milk at 80-85F, how long does it take to thicken up to a pH of 4.8?
Title: Re: sudden drop in PH
Post by: Devon on June 04, 2012, 08:24:11 PM
4.8 is the end result, I remove from the press at 5.3, put in frig and usually overnight hits 4.8
Title: Re: sudden drop in PH
Post by: FRANCOIS on June 04, 2012, 08:27:45 PM
Really, a fridge at or below 40F?  That's amazing, you should isolate your own starter from that and use it for camembert.  I'd buy it.
Title: Re: sudden drop in PH
Post by: Devon on June 04, 2012, 08:29:14 PM
I put them in my cave at 48 - 53 degrees, I have not been putting them in the main frig. Should I be putting them in a frig with a lower temp? It is funny the stopping point is always 4.8 to 4.9
Title: Re: sudden drop in PH
Post by: linuxboy on June 04, 2012, 08:31:17 PM
If you cold crash it to 40 in a reasonable size wheel and it still drops .5? After salting? I've only ever seen that in some strains of acidophilus and bulgaricus, never in a meso. If your pH readings are correct, that is some crazy synergistic effect or strain you have there.

Try the milk alone at that temp and time how long it takes to get to 4.8 Better yet, see if you can take some readings throughout and plot a pH curve.
Title: Re: sudden drop in PH
Post by: Devon on June 04, 2012, 08:34:03 PM
Remember when I posted about two different reading on two different meters? You told me one of the probes must be bad and I received a new probe and it corrected the problem. This is the reason I ended up with two meters. I run cal on both meters before each make. I will split the make this weekend, I will use Ma 16 in one and will not use any starter in the other. Worst thing that can happen is the same result.
Title: Re: sudden drop in PH
Post by: linuxboy on June 04, 2012, 08:39:42 PM
Okay, but if you want, heat up some milk (a pint), to 80-85F, and put it in a pot of 90F water, and see how long it takes to coagulate. This will roughly mirror your make. You can take pH readings based on time directly in milk, and it will tell you ahead of time how the make will behave in terms of pH. Basically, am saying that there's no need to do a full make if you just want to determine pH behavior or your native flora.
Title: Re: sudden drop in PH
Post by: Devon on June 04, 2012, 08:48:55 PM
Good point, I will stop by and pick up a gal on my way home from work. I will let you know how it goes. Thanks for all the input a lot to absorb but I am determined to figure this out.
Title: Re: sudden drop in PH
Post by: Devon on June 06, 2012, 04:07:25 PM
Raw milk PH data
Temp   Time      PH
88.1   4:30 pm   6.75
89.8   5:00 pm   6.74
89.4   5:30 pm   6.73
91.2   6:00 pm   6.72
91.0   6:30 pm   6.70
91.2   7:00 pm   6.69
91.2   7:30 pm   6.68
90.4   8:00 pm   6.67
90.02   9:00 pm   6.65 Milk was thickening
89.5   9:45 pm   6.60
89.2   10:15 pm   6.26
89.0   11:00 pm   6.12
89.5   11:30 pm   6.05
89.7   12:00 am   5.84
90.1   12:30 am   5.78   
Went to bed @ 12:30 am
78.5   7:00 am   5.38   

Decided to do a two gal make while I was monitoring the PH level of the milk. I cut a steel press wheel and barrowed a 4 inch hoop from a friend. I did not use any starter, the Ph drop was slow so I missed every target PH.
4:30 pm heated to 88 degrees PH 6.75
Held for 45 minutes PH 6.74
Added 1/4  teaspoon of Rennet  6.74
Floc 14 minutes cut at 42 minutes PH 6.73
Held 5 minutes, heated to 102 degrees over 50 minutes PH 6.69
Held for 45 minutes PH 6.68
Drained and added 1 1/2 teaspoon salt – Note PH dropped by .05 right away PH 6.63
Cheddared for 80 minutes PH 6.59 and pressed overnight PH 5.32 when removed from press this morning.
Left cheese out at room temp to dry and PH is 5.23 as of 5:30 pm today.
It dawned on me last night the only recent change I have made was the salt I was using, I went from using canning/pickling salt to using Morton flaked salt. It was interesting to see a quick drop after salting.

I think the press is a little over kill for the 4 inch hoop.
Title: Re: sudden drop in PH
Post by: linuxboy on June 06, 2012, 04:30:50 PM
That's about a normal pH curve for those temps.. I wonder if your previous pH drops were just normal for the heavy load of raw+ added inoculant.
Title: Re: sudden drop in PH
Post by: Devon on June 06, 2012, 05:40:34 PM
So what would your recommendations be for the next make to reach a 5.2 – 5.3 finial PH? Leave out the starter, reduce the amount used? Any other changes?

Strange that I have to worry about a salted cheese in the press, I guess I won’t be pressing overnight.
Title: Re: sudden drop in PH
Post by: linuxboy on June 06, 2012, 06:02:45 PM
exactly. Use less, leave out altogether, or use lower temp schedule. Same principles apply as Francois posted. If you are having runaway acidity, then if it's not temp or salt schedule, it's the bacterial load... either amount or how it plays along with temp, or synergistic effect with the raw milk+ commercial starter that you added.
Title: Re: sudden drop in PH
Post by: Devon on June 06, 2012, 06:07:18 PM

So how far off was the 2 gallon make that I listed a couple posts ago, in regards to the PH markers? I can slow down the make to stretch out the PH markers some but don't think I will be able to meet standard markers. It would be a 10 hour make plus pressing which it sounds like I have to monitor very close. It would be nice to sleep somewhere in there.
Title: Re: sudden drop in PH
Post by: linuxboy on June 06, 2012, 06:17:49 PM
Then do a few batched of milk where you put in .2, .5 .8% etc bulk, and see how it behaves. Try to get it to how you want it until the times and pH line up.
Title: Re: sudden drop in PH
Post by: Devon on June 06, 2012, 06:21:39 PM
Great thanks for the help, a cheese to you. I will do two 4 gal makes this Saturday and let you know how it goes.
Title: Re: sudden drop in PH
Post by: linuxboy on June 06, 2012, 07:41:31 PM
Based on the raw milk results, it looks like you're overpitching with a culture that really likes the higher end of meso temps. So, using less commercial starter should work well.
Title: Re: sudden drop in PH
Post by: Devon on June 09, 2012, 06:48:04 PM
8 gals raw milk PH 6.74 heated to 86.9 degrees F
Added 1/8 teaspoon MA 016
Held at 86 degrees F for 40 minutes PH 6.71
Added 1 teaspoon liquid animal single strength, floc in 20 minutes
Cut at 60 minutes into 1/2 inch cubes PH 6.63 rest for 5 minutes
Raise temp to 100 degrees F over 45 minutes PH 6.60
Held for 40 minutes PH 6.31
Drained and cheddared for 60 minutes PH 6.01
Salted (5 tablespoons) and pressed at PH 6.01

Pressing hour 6, is fairly dry and the PH from the cheese is 5.30, removed from press and placed in main refrigerator. The next make I will drop the starter to 1/16 teaspoon.

As I still struggle to adjust the starter on cheddar, at least on a brighter note my Jarlsberg and Baby Swiss turned out great.
Title: Re: sudden drop in PH
Post by: Boofer on June 10, 2012, 12:23:37 AM
Very nice cheeses. A cheese comes to you for such a finely crafted pair of alpines.  :)

-Boofer-
Title: Re: sudden drop in PH
Post by: Devon on June 10, 2012, 06:13:20 AM
Thanks Boofer,

I was pleased to find the final PH of yesterdays cheddar make sitting at 5.22 this morning as the last 8 makes PH has dropped below 5.0.
Title: Re: sudden drop in PH
Post by: FRANCOIS on June 10, 2012, 04:55:30 PM
Just to nit pick---don't take it personally---there is what looks like some minor cracking along the eyes of your swiss.  This is a major issue for commercial producers.  The root causes are many and varied but it is indicative of gas continuing to form after the hot room.  This, when extreme, can lead to crumbly edges around the eye formations and flavour defects (in extreme circumstances) leading to sour notes.  In super extreme cases the cheese actually cracks itself apart.
Title: Re: sudden drop in PH
Post by: Boofer on June 10, 2012, 05:41:22 PM
I saw that in the Jarlsberg, but not the Baby Swiss. There was a discussion on eye-splitting about a year ago.

Still, good stuff.

-Boofer-
Title: Re: sudden drop in PH
Post by: Devon on June 10, 2012, 07:29:07 PM
I noticed that in the Jarlsberg, it must have taken place in the warm room because I cut them in half to fit in the gallon vacuum bags, they were 8 lb wheels and would not fit otherwise. Then moved them to the cave. I am not sure what caused it but I have a theory about it, there was a 1/4 inch long crack on the side of the wheel that appeared the 1st week in the warm room. My thought is the gas was escaping there and the pressure in the wheel was equalizing via the lowest pressure point inside the wheel and finding its way to the crack creating internal cracks along the way. Either way it still tasted great. The baby swiss had no cracks anywhere.
Title: Re: sudden drop in PH
Post by: Devon on October 21, 2012, 05:09:34 PM
I figure I would give an update on the cheddar PH levels. I am pleased to report thanks to LB and all the folks that gave advice, that we have success again at making cheddar. I have been able to achieve finial PH levels of 5.2 to 5.3. Cheddars only three months old have great flavor and aroma, should age out very well at one to two years.

The below photo is a 3 month old cheddar and a picture of the lower cave with several more resting peacefully.

Thanks again to everyone.
Title: Re: sudden drop in PH
Post by: bbracken677 on October 22, 2012, 05:19:14 AM
Very nice! And a very informative thread for cheddar makes! 

Thanks and a cheese for you!