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That's really strange.
I don't think that holding the curd in whey for a substantially increased time is going to do any favors as the texture will be so different. But I also don't know a whole lot about pH deviations during the cheesemaking process. Hopefully someone else will chime in.

A couple other thoughts -
What do you use for culture? Source, type, etc. Wondering if it's ineffective due to age, temp shock during transport, etc. Was it purchased during the summer? Have you tried a mother culture, or a different culture source?

I know I asked about sanitizer residue already, but what type are you using on your equipment? Do you rinse before milking or not?

Have you tried something like yogurt or clabber with the milk? How does that turn out?

Just grasping at straws here...

I asked the cow discussion board about milk testing in Canada, no response yet.

The tests you've been running are food safety tests (E coli, Salmonella, etc).
If your cow is healthy and you have a good routine for milking and sanitation I personally don't think those need to be run regularly as the possibility of one of these organisms appearing in a single cow operation is so so low. But if you sell milk or need peace of mind they are good tests. 

Those organisms typically appear because manure got in the milk or the cow is sick. Definitely smart for larger operations to test, but not really relevant in my opinion for a family cow.

QuoteMy cow's pH this morning was 6.99. Im making Leerdammer from 200 Easy Cheese recipes and holding at 40/104 until it gets to 6.3 as per Caldwell. Going on 2 hours  now plus the 1 hour of stir time and its still at 6.78.

What temperature is the milk when you are measuring initial pH?  Caldwell explains that cold milk will read a higher pH than when it is warmer.  Assuming the milk pH is 6.99 at ripening start temperature, my deductions are that it is not going to reduce to 6.3 in the same time frame, if ever, as a milk with initial pH of the more normal 6.6.

QuoteSCC can be tested cow-side (or at home) with a Portacheck or CMT. I don't have much experience with Portacheck. The CMT is cheaper and more common but the threshold is 250k+. So it's great for showing acute mastitis cases but not necessarily going to detect a subclinical case. However, a SCC of 250k or below theoretically should not be an issue for cheesemaking. But some strains - like Staph A - can interfere with cheesemaking in other ways (enzymes, etc) but are hard to detect with a CMT since the SCC will often be right around 200-300k.
That's why I recommend a lab SCC test for situations where milk quality is questionable but the CMT is inconclusive.

To glean more understanding of how high SCC affects cheesemaking, I went back to Caldwell's "Mastering...." book.  If I have this right, not only does high SCC affect pH, but the cells attack bacteria which may mean they are adversely affecting the starter culture...and thirdly, they produce enzymes which break down some of the protein structure which leads to poor cooagulation.

Again, Teresa and Susan, you are not alone in using milk with a high pH...I've done it quite a bit and as I say I do accept a bit higher pH targets than usual.  I never have had a coagulation problem though.  But what I don't understand is further in the process when pressing I get super quick pH drops and frequently I miss the ideal pH if I am not careful.  I'm not sure if this is another piece of the puzzle or something entirely unrelated.  BTW these cheeses come out OK, acceptable, meltable, good flavor but I would say the texture is a bit off...sometimes a bit too firm, sometimes a tiny bit chalky.  It just seems weird to have issues with too high pH at the beginning of the make and too low/too quick at the end of the make.  And wondering if it's the milk quality that is affecting all of these issues.

Milk testing in Canada...
Hope this helps.
https://familycow.proboards.com/thread/100070/milk-testing-canada?page=1#post-1063454

The Vermont Cheese Council is hosting their annual conference online this year (next Friday).
$65 for 6 speakers/topics, several very applicable to this discussion.
http://vtcheese.com/conference/

Hi all,

Thanks for all your thoughts.  Sorry for delayed reply it was our once yearly snowfall and freezing temps so we are never totally prepared.

Chetty: Jez is 4 years old. I'll post some pictures. After you asked about the calibration fluid I realized that I hadn't changed it for a while. It was looking a little icky so I mar up a new batch.  I was thinking about that as well.  The solution for the "7" is actually 6.86. I couldn't easily find anything that was 7 and I think when in was researching it seemed that 6.86 was the standard for 7. If that is wrong I will go looking again. Maybe I need to bite the bullet and buy Extechs solutions. They are just expensive comparatively. I calibrate at room temp (about 20-22C), 2 point, 4 first then 7 as per the extech manual.

After I changed the fluid I checked some milk/cream combo 3L whole milk/1L cream) I was heating for cream cheese. The pH was 6.81 at about 25C which is the lowest I've ever seen it. I'm not sure though if the cream amount would alter the pH.

Bantams: yeah I'm not sure how this cheese will turn out, I just don't know what else to do when the pH is so far off what it's supposed to be.
Cultures are from biena or danisco. These particular ones were shipped in winter so should have been ok. It was ThermoC and proprionic.  However it seems to be any culture I've tried. I've not tried a mother culture or yogurt.

Here's my milking procedure: pre rinse milker with about 10L hot water and a capful of bleach. Milk. After milking 10L lukewarm water rinse, then 10L chlorine based detergent rinse, then 10L acid rinse. They are dairy products. 

I checked her CMT, nothing obvious.

Selling raw milk in Canada is illegal but there are many micro dairies that practice civil disobedience but with excellent hygiene and data (monthly cultures) as per RAWMI standards to back up the safety of their products. 

I did realize that the food safety package doesn't test for Strep or Staph so I many run a culture to rule out a sub clinical infection.
After reading your link, I will ask my vet if they can also run an SCC. Failing that I found a source for the PortaSCC which wasn't prohibitively expensive so I may order a small kit.

Susan38: my cheeses are "just ok". I'm not super happy with them. Texture is ok but they often to me have a weird under taste. No one else can taste it but I seem to be one of those super-tasters. Almost like the smell of plastic. IDK if that is related or not. So I'm investigating. I also have trouble knowing what amount of salt to put in as my yield is less and a lot of the recipes just call for an amount, not by weight of curd. I may be under salting for fear of oversalting so lately I've been using more salt to see if that changes the tastes.  That's another story.

Thanks, all!

My goodness! She's a beauty!
Is she a show cow?

Has she ever had ketosis issues?
Do you supplement with Vitamin E when she's on hay (vs pasture, which has ample Vit E)?

Both ketones and Vit E deficiency will cause major off-flavors. Ketones will also cause high pH but it's typically a temporary thing as the cow will also be sick. But just thought I'd mention it as she looks like a big producer who maybe has trouble holding condition.

Thanks! You are now officially my favourite person for being enamoured of my cow 

She isn't anything aside from being lovely. She is actually a dairy reject. They couldn't train her out of sleeping in the gutter so wanted her to go to a home where she could have more pasture and a barn that didn't require free stalls.

No history of ketosis. She actually doesn't produce as much as I've seen many people post. Right now in the (relative) cold she is giving about 18L/day and when all is perfect about 21L. She has one quarter that doesn't produce nearly as well as the others. More than enough for us though!

She gets organic grain, organic alfalfa pellets, kelp, dairy minerals, medium quality hay and a big flake of high quality hay at each milking. They have a high selenium salt/mineral lick available. No off flavours in her fresh milk. No vitamin E but I recently came across that on some cow boards and was considering it. Do you have a dose for that? If its not off the top of your head, no worries I'll look it up.

She's not too bad of a keeper. The herdsman who came an AId her was quite surprised at her (good) body condition. I guess he's used to seeing cows a whole lot skinnier than she is.

Cheers,
Teresa

Looking at how pretty that cow is, my money is on the ph meter.  I have a love hate relationship with them when they work there great but I've owned 4 different brands different price ranges and still haven't found one that I trust 100%.  My current meter was a 300 dollar spear tip meter.  I've had to replace the probe which was another 200 dollars and I still have trouble.  I have not had the brand you use but I think I would start there.  New calibration fluid check Amazon you can get some reasonably priced. Clean the probe sensor  check the glass over there is a tiny spot on the glass that is most important to be clean as it is where the testing occurs. 

QuoteI calibrate at room temp (about 20-22C), 2 point, 4 first then 7 as per the extech manual.

I have an Extech 110, maybe different model than yours, but the instructions for mine are to calibrate at 7 first, then 4.  I think I did it the other way around once, and the subsequent measurements were way off.  Could the problem be as simple as this?

That's how all my different ones were calibrated too. In fact mine wont let you do it any other way it looks for 7 then it searches for 4. 

Interesting. I will double check as I even wrote on my jars 4 first. 

OMG seriously?!? It does say 7 first. Facepalm. I love you guys.

Will report back...

pH meters are notoriously hard to calibrate/clean.  I've owned 2 in the past.  When I started cheese making, even though I knew the advantage of using a pH meter I decided it was easier to go without.   With your own cow, I think it's definitely a thing you want, but I recommend assuming measurement error before you wonder what's wrong with your cow/milk.  Especially if your make is proceeding normally, that's a good indication that your meter is just not giving you good readings.

A couple of tips: The probe has to be immaculately clean.  Salts on the probe will basically screw everything up, as will fats and proteins.  Don't store your probe in tap water.  Different probes have different care requirements, so be sure to follow the instructions carefully.  To get the best measurements, you probably should clean and calibrate the probe before every use.  Some probes are more finicky than others, so you may need to do it or not.  If you are getting weird results, assume the probe is dirty/miscalibrated/damaged unless you have some other factors to back that up (as frustrating as that sounds).

pH also depends on temperature and the temperature you calibrate the device at is very, very important.  Some devices have a temperature probe and adjust for temperature, but you still need to be careful about the temperature you calibrate at -- because the temperature probe may not be correct.  Always measure temperature with a different (tested) device.  Good digital thermometers can be calibrated as well, so do the boiling water/ice water calibration on it.  Even if it can't be calibrated, make sure to test it because some devices are off by a huge amount (this will help your cheese making too).  When calibrating your pH meter it is very, very important to follow the directions for the temperature of calibration exactly, because it will differ depending on the device.

A very important point: if your device does not automatically adjust for temperature, you must do so manually.  Otherwise your readings will just be wrong.  So you calibrate at a certain temperature, take the temperature of your sample, measure the pH, look up the *actual* result in a table (which hopefully came with the device -- otherwise I think there is a table in Caldwell's book, or you can look for one online).

When making cheese, there are several points in the process where you can get a gut feeling for pH.  Learning to understand these helps a lot (and is pretty much necessary if you don't have a pH meter).  Here are a few pointers:

Milk coagulates due to acid at different pHs depending on the temperature.  Roughly, at room temperature it's 4.6, 50 C is 5.2, 80 C is 6.0.  Those are not correct -- I wish I could find a good table of actual values, but they are close.  This means that you can test your milk simply by adding a starter culture and occasionally heating small portions of it to various temperatures over time.  Then you can cross reference that with your pH meter to see if it is agreeing.

Similarly ricotta cheese forms best at a pH of 6.0.  A good test of your drain whey pH is simply to make ricotta.  If it doesn't start to curdle at around 85 C then it is up over 6.0 by a fair way.  If it curdles nicely at that temp, then you know you are around 6.0.  If it gets grainy and sinks to the bottom, you know you are under 6.0 by a fair way.  (It's a fair whey that tells you it's own pH...)

Rennet coagulates milk at a fairly regular rate depending on rennet amount, temperature and pH.  So you can get a feeling for the pH of the milk simply by measuring the flocculation time (assuming your rennet is in good shape).  Always measure flocculation time using whatever method is most consistent for you.  That way when it changes you know that something is wrong -- likely with the pH of your milk.

However, you can also do experiments on flocculation time.  Add a starter culture to milk.  Pour the milk into several small containers with a wide mouth (like coffee cups -- 250 ml each).  Hold the temp at 36 C in a water bath.  At regular intervals (say every 30 minutes) add a drop of rennet (which will make it 40 IMCU per liter) to one of the coffee cups.  Put a soda cap in the cup and measure the time to flocculation (for me that's until it won't spin any more and it *just* leaves a mark when I take it out -- that's a bit longer than most people, I think, but it is repeatable for me).  Record the flocculation time and measure the pH.  This will give you a good sanity check on the pH.  I forget what the standard is, but I *think* it's something like 12 minutes at 36C and a pH of 6.5.  If your pH measurements are way off, it will be pretty obvious.  BTW, this is literally how they define IMCU, though there are other testing methods you can use as well.

The taste of milk changes as the pH drops as well.  This is pretty subjective, but I've been surprised at how much control I can get.  I'm actually pretty good at detecting sugar.  I used to brew beer a lot and when I was active I could actually tell you the specific gravity of the wort within about 1% either way just by tasting it.  Practicing tasting can give you a pretty powerful diagnostic tool.

Milk is sweet due to the lactose in it.  As the starter culture metabolises the lactose, that sweetness goes away.  In its place you get acidity.  Sweetness is much, much easier to taste than acid, unfortunately.  When I first started, I lamented the fact that I couldn't really discern acidity very well.  It wasn't until I read Jim Wallace's description that I realised the trick -- concentrate on sweetness.

At a pH of 6.0 or higher, milk tastes like milk.  As the culture gets established, I find that around 6.0 I can start really picking up the aroma of the fermentation products -- this is probably not to do with the acidity at all, but it can tell you how active the culture is.  Below 6.0, it starts to get less sweet.  As is gets less sweet, you start picking up the milk fat flavour in the milk -- previously it was masked by the sweetness.  As it goes lower, you start to pick up a little bit of bitterness.  Again, the natural bitterness of the milk is masked by the lactose sweetness.  There is also a phenomenon of bitterness-sourness confusion.  Things that are sour at a low level are often perceived as bitter.  So if you are picking up on that bitterness, it's because the sugar is going away and the acidity is coming up.  At about 5.4 - 5.5 the flavour is neutral (I don't know exactly, because I don't have a pH meter :-D ).

As the pH goes down from there it starts to pick up more acidity.  It is much easier to measure the pH of the whey than the curd, so you should always measure the acidity of the whey as a sanity check against the curd, IMHO.  There are a couple of problems, though.  The whey has been draining over time, and will acidify differently outside the curd than it does inside the curd.  The curd contains protein (duh ;-) ) and protein tends to buffer the pH.  This means that the pH of the curd is always *higher* than the pH of the drained whey.  So don't be confused when you measure it and that happens.  Strangely someone mentioned that when they measure they get the opposite and I'm not sure what that means :-)  Possibly that their probe doesn't work very well for curds...  You can also verify this by tasting.  Especially just when the whey is getting tart, the curd will still have a neutral/buttery flavour.

Finally, the curd undergoes changes as the pH drops.  I wish I could remember who explained this to me (on this very forum!) because it blew my mind at the time.  Curds knit more or less easily based on 3 factors: pH, moisture level and temperature.  Despite all my preconceived notions, that is the actual order of importance (at least at temperatures under the melting point of the curds).  pH is king.  Nothing has improved my cheese making more than understanding this point.

At a pH of 6.0 and above, curds knit very, very fast (from separate curds to a consolidated slab in 15 minutes with no weight on them).  At a pH of 5.3, they don't knit at all unless they are very high moisture, very warm and/or have a fair amount of pressure on them.  You can guess the pH of the curd simply by watching how the curd is knitting.  If your pH meter is reading 6.0 for the curd, you can just cut it and stack it and see if it melds into a slab in 15-20 minutes.  If so, then the pH meter is right.  If not and they just sit there as two pieces, then the pH meter is wrong.

I hope some of these tips are helpful!

Hi all,

After making sure my meter window was clean and calibrating it correctly, pH of fresh milk cooled to room temp 22C was 6.89.  So still a bit high.

My vet is going to run SCCs for me and we are also going to culture for organisms outside the food safety screen.

Mikekchar: thanks for your detailed reply.  Her milk is frustrating and makes have not gone as they should have which is why I got the meter. Trying to science her milk.
This probe does have a temperature sensor. My three thermometers are ice bath calibrated and agree so at least I got that.

The meter so far seems to be accurate with the things I make at room temp like cream cheese. I often miss the actual point of first coagulation (there is a lot of whey on top by the time I get to it) so it's sat a bit too long and the meter was giving me a 4.5-4.55 so I thought that seemed right. 

The flocculation test seems easy for a meter check. I'll try that. My determination of flocculation is like yours and it's usually right around 12 minutes at 30C if I use the recommended amount. I was reducing the rennet amount a bit but my last few makes the flocc time increased to 14 mins so I'll go back to the regular amounts.
Is doing the 36C flocc several times just so you can see if you have repeatable results for pH?

I think that was me with the whey apparently being 6.6 but the curds said they were 5.3ish as they had that cooked chicken breast texture. They also took a shwackload of pressure to knit so they were obviously way down there.

The other tips are also great. I'll try to put some of them to use in my next batch!

Cheers,
Teresa

Small update,

Cultures for Staph and Strep came back negative. Their SCC counter was sold by the boss unbeknownst to my vet so he is looking into where I can get SCCs done.
pH at 19C today was 6.81. A farmhouse cheddar make went reasonably well pH wise but I did add half again as much culture.

Cheers,
Teresa