Pressing vs PH Markers question

[Knittingjidda]

For my colby, the final press was to be 12 hours at 50lbs. After an hour, I hit just below my ph marker (goal was 5.4-5.5, and I was at 5.3+ ish). There was still a bit of whey, but I went ahead and stopped pressing anyway. I hit my ph markers all the way through at about the right times in the recipe (found on forum based on Caldwell). What should I have done, keep pressing until there is no more whey or stop when I did? Summer kitchen temperature is in the 70's (mid-atlantic) and I'm using regular P/H skim milk with cream. Curds were salted at 2.25% of curd weight if that helps.

[Bantams]

If your curds were salted before going in the press, then there's not much that will change your pH at that point. Stopping the pressing process certainly won't do anything (different story if you stop pressing to then brine cheese. Salt = primary means of halting pH drop at end). Actually, halting the press probably made it worse as excess whey in a wheel will further drop the pH.

You should have kept pressing for the full time to ensure a complete knit. One hour pressing will likely leave you with a cheese that is too high in moisture and susceptible to internal mold issues.

If this was a cheese that was to be salted/brined only after pressing was complete I probably would have split the difference and pressed for a shorter time ~4 hours and then brined. And made a note and next time tried to keep pH higher in the vat.

[Knittingjidda]

It had been pressed for a few hours prior to that final 50# press and was well knit. It was salted, but the ph was dropping fast. I checked the the ph meter and tasted the whey runoff. I’m not sure why it kept dropping so fas after salting It was a bit of mm100 and Florida Danica.

[Bantams]

Gotcha.
Can you post your recipe? I don't remember GC's Colby having salted curds (only brining after pressing) but I'd have to find my book to verify.

[Knittingjidda]

1.75 gallon skim milk + .25 gallon cream
1/2 tsp CaCl2
3/16 tsp mm100
1/16 Flora Danica
1/2 tsp calf rennet (Her recipe called for 1/4tsp)
1/8 tsp annatto (not in recipe)
2.2-2.5% of curd weight salt. I pretty much followed her make procedure (cold water washed curds). I hit the ph targets for each step, so thought I would stay on target. The salt is added in two parts with about 5’ in between.

My last batch was much wetter, so I focused more on the stirring this time. I had a bit over 1.6 kg of curds after draining. When I pulled it from the press it weighed almost exactly 1 kg.

I’m going to try to figure out what I can change next time so I can press longer. Today it’s damp on the bottom, but not drippy and the sides are getting those darker drying patches. I did move it straight to the cave instead of drying at room temp.
My first Colby was from the cheese making.com recipe. The second was from the forum. This will be my third Colby. So far each is getting a bit better, but that rapid ph drop took me by surprise.

[Susan38]

Hi, I'm jumping in here as I have similar issues as Knittingjidda.  I've about 20-30 salted curd cheeses under my belt and the pH continues to drop while pressing.  Thus pressing times are quite shorter than what reads in the recipe to hit the target pH.

I've seen similar posts in this forum, and have yet to read an answer that fully explains the situation.  Speculations on my part include:

1.  Perhaps I am not salting enough, as I haven't really done it by weight, but rather by using the maximum amount (volume) the recipe calls for.
2.  Maybe there is a lag time involved?  Perhaps for whatever reason the pH curve is really cranked at the time of draining and salting, and it takes a bit of time for the salt to kill off the bacteria and thus the pH continues to drop?
3.  There is a difference in the whey pH (which is roughly 0.1 to 0.3 higher or more? than the curd pH).  It seems intuitive that the more whey is removed, curd pH would also lower?  In other words, a curd with more whey incorporated inside would measure a slightly higher pH than a curd with less whey inside?  So as you continue to press the whey out of the curd, there would be an associated pH drop?

I'm probably overthinking this, but it does really puzzle me why there are some of us with this problem consistently occurring, with no answer as to why this is occurring, and no definitive solution.

What I have done meanwhile, which seems to help, is to use the high end of pH markers as my guide (say, if it says to drain at pH 6.3-6.4, drain at 6.4 and even 6.49) and that does seem to help extend the pressing time a bit without going under the final pH target.

[Bantams]

http://cheeseforum.org/forum/index.php/topic,11440.0.html
Looks like others have had the same problem.
I've tried many recipes from GC's book but not this one so can't provide further insight.  May just be a bad recipe.
I got confused because I make the "same temperature washed curd cheese" from her book and call it "Colby" because I thought that's what it tasted like.  And it doesn't call for salting the curds, just brining the whole wheel at the end.  Maybe give that recipe a go?

@Susan38 If you've made that many, you must have one ready to sample? How's it taste?

[mikekchar]

I can't remember who it was, but they said that they moved from Flora Danica to Kazu when making Colby and it helped the acidity problem.  It may be that Flora Danica is more tolerant to salt.

[Knittingjidda]

I salted by weight and it was a lot more salt that what she said for the amount (she gave a percentage as well). She said 2.2-2.5% salt, but also gave 1-3 teaspoons which was a fraction of what I used.

The experimenting is fun though. I'll aim for the higher ph for starting to press next time. This time I was focusing on getting the curds well cooked and a bit dryer than last time.

I would think waiting to brine instead of salting the curds would make the issue worse as nothing would inhibit my ph nose dive... I have this issue with almost all our cheese a gradual drop followed by a nose dive in the press. Even our cultured mozzarella does this after draining the curds.

I do use supermarket skim + cream and we have a warm kitchen in the summer. Maybe this is affecting it as well.

There isn't much Flora Danica, but I can just use all MM100 instead, or try the Kazu.

[Susan38]

@Susan38 If you've made that many, you must have one ready to sample? How's it taste?

I just looked at my spreadsheet and it turns out I've made sbout 20 salted curd cheeses over the past few years.  Farmhouse cheddar, stirred curd cheddar, several different Jack recipes, several different Colby recipes...all that called for salting the drained curd prior to pressing.

First ones were without pH monitoring, and using New England Cheesemaking (NEC) mesophilic culture, and all turned out too sour, dry and crumbly.  Next ones I used pH strips which with those I found out I was overshooting the final pH during pressing.  Final ones using pH meter I was able to monitor throughout, most hitting pH targets for ripening, cooking, draining, etc. and then chasing the pH during pressing.

Final results/tasting had a lot to do with what happened during the entire process, not just during pressing.  I've posted all my results thus far...but bottom line is that the most successful ones were the ones I pulled from pressing to try and hit pH, which had I left it to press per recipe time guidelines would have tanked the pH too low I'm thinking.  Although a few I pulled per pH but in hindsight think they were a bit "underpressed" like my last Gouda, which tasted great but had small holes due to curds not properly knitting together.

After using NEC's mesophilic culture and learning it was a "fast acidifier" I looked into other cultures and started choosing the "moderate" and "slow acidifiers" and it has helped quite a bit with final results and increased pressing times.  Flora danica and Kazu have both been much slower acidifiers for me in my cheesemaking environment than the NEC mesophilic.

I would think waiting to brine instead of salting the curds would make the issue worse as nothing would inhibit my ph nose dive... I have this issue with almost all our cheese a gradual drop followed by a nose dive in the press. Even our cultured mozzarella does this after draining the curds.

I agree, as that has been my experience.  Consistently. 

I'll aim for the higher ph for starting to press next time.

I would aim for higher pH throughout the process, not waiting till press time.  Those pH curves start out at the beginning and speed up toward the end, so keeping the pH at the higher end of target at the start might influence the pH toward the end?  My experience thus far anyway.

I got confused because I make the "same temperature washed curd cheese" from her book and call it "Colby" because I thought that's what it tasted like.

I think the recipe you are referring to is more of a Havarti or St. Paulin style, based on her introductory discussion for that recipe in her "Mastering Artisan Cheesemaking" book?

So anyway getting back to the issue at hand, for example let's look at Caldwell's "cool water washed curd" recipe in her "Mastering Artisan Cheesemaking" book.  I believe it's close to a Jack recipe.  It calls for salting the curds after draining.  At draining, target pH is 5.7 to 5.8.  Then you salt.  Then at Mold and Press, final cheese pH goal is 5.4 to 5.5.  So you see there is acknowledgement in the recipe that pH will drop during pressing, even with salted curd.  I think the issue at hand is that the recipe calls for pressing for 12 to 24 hours to reach this goal pH, when in my experience it takes 4-6 hours at most to reach that pH.  I am looking for an explanation as to what is happening to make the pH drop between salting and pressing, and more importantly why that pH drop is happening so much more quickly in my cheesemaking experiences as compared to the recipe guideline times.  I believe there are several of us that are struggling with this issue, and thanks Knittingjidda for bringing the subject up again!

[John@PC]

Some very helpful and insightful analysis in this thread.  Susan, you must be (or have been) a science teacher / professor .  Since I've returned from my hiatus from cheesemaking I'm appreciating more and more the role of acidification profile in outcome.  I've made over 300 batches (1 to 5 gal) of almost every generic type and I'm pained to think of the ones that turned out bad or "not-so-good" because of relying on time, temperature and pressing primarily.  Like you Susan (and I'm sure many others here) it took me awhile to start tracking pH but even then I used it more as an effect rather than a cause if you know what I mean.  As Yoda would say, "The light I now see"  .

[Knittingjidda]

Thank you for your insight Susan. All of my first cheeses suffered more from the dry and crumbly result of following time. Our first clue that someone wasn't quite right was when we did our first cultured mozzarella and it was in the 4's after 30' (I had a few ph strips to try out). Since then we bought a ph meter and have been trying to fit ph targets to recipes to see how to improve. Every cheese turns into another learning experience. Next colby, I try to stay a bit more ahead of the ph and still try to get the curds to the proper texture. Should I shift a bit more towards Flora Danica instead of the MM100? My first Colby was using the cheesemaking C101 and had good flavor. My last two used a combination of MM100 and Flora Danica.

I'm grateful to have access to all of the experience documented in the forums.

[Mornduk]

I am looking for an explanation as to what is happening to make the pH drop between salting and pressing, and more importantly why that pH drop is happening so much more quickly in my cheesemaking experiences as compared to the recipe guideline times.

You might want to look at the ambient temp. It might be that your house is "warmer" than hers
I haven't got any cheese making experience at all compared to you, but I've been making salami for years (and fermenting the culture under controlled temp and humidity until it hits its pH target). When temp goes up pH curves "shift to the origin", so not only does the pH drop faster, but the "accelerated drop" phase starts earlier.

The main reason I think this might be it, is because something similar happened to me with Caldwell's book. On the first six cheeses I was always hitting my targets way later than she suggested. Then I tried a couple of cheeses that asked for pressing under specific warmer temps, and I hit her times almost perfectly. So under a specific temp we both had the same times, but under "room temp" I was way slower, which probably means that we love the AC way colder than she does Anyway hope you solve it soon!

[Susan38]

Knittingjidda--I'm still trying to figure this all out too!!  I learn so much just in having these discussions with others...there's always another point of view or new tip or trick I haven't considered.

As for cultures, I have never used MM100 but I have a "cultures guide" I found on-line http://artisancheesemakingathome.com/pdfs/cultures.pdf that considers it a "moderate acidifier", and it says the same for Flora Danica.  I use Flora Danica for Colby with great flavor results, and it is slower to acidify as compared to the NEC mesophilic culture (C101).  And for me, the Kazu and Meso Aroma B cultures seem to acidify even slower than Flora Danica.  I have to be careful with MA11 as it can be almost as quick as C101.  Those are the only mesophilic cultures I've had experience with to date.

But, as you'll read in other posts here, you might have different experiences than me using the same cultures...because of potential differences in milk, climate, etc...so keep track of what happens in your own cheese makes using the different cultures.   

And in the quest for slower acidification, you might try what I've heard others recommend... to back off on the amount of culture to try and slow the pH curve/development down.

Yes I agree every cheese make is a learning experience and for me that is half (or more) the fun of it.  Each time I try something to correct a problem in a previous cheese and that always leads to a new adventure.  Good luck with your next Colby, however you decide to proceed in making it, and please let us know how it went (including your pressing time to target pH, of course, ha!)

[Susan38]

Mornduk--Good point, I have tried to keep pressing at always about 72 degrees F air temp but of course that varies a bit.  I will keep better track of that in the future to see how it plays a role in the pressing/pH dilemma.  Thanks for checking in on this subject.