Chevre - Draining pH & Lactic Curd Description Discussion

[george13]

The wiki chevre recipe has the drain point for chevre at 5.4 - 5.5.  In reading other posts from some of the more experianced members as  the optimal drain point being 4.5 - 4.6.  I believe that it is a considerable difference in acidity and ultimatelly in flavor.  Any thoghts or advice would be greatly valued.  Thanks

[Cheese Head]

There's some info in our Wiki: Coagulation article saying for lactic acid cheeses like Chevre final pH should be 4.6-4.7 and there's some more detailed info here from member linuxboy for Chevre drainage points.

[iratherfly]

The final drain point should definitely be in the 4.5 to 4.7 range.

[george13]

Thanks, here is my follow-up question on that if you don't mind.  My last batch was at 4.6 pH, six hours into culture incubation.  My guess is that because it's summer and the ambient temp is around 80, the culture was more prolific.  The curd however was not at optimal firmness.  What do you recommend in such a scenario?
1.  Do you increase the rennet so as to get a better firm in the given duration of time (6 hours), or
2.  Do you let it go for the recomended 12 hour interval and accept a somewhat more acidic final product.

It would be great if I can have the perfect 73 to 76 curing temperature for 12 hours, but this time of year it is not feasable without the introduction of additional cooling equipment and expenses, so I feel I could somehow manipulate the process.
Thank you

[Cheese Head]

george13, just reread your OP, my bad on that Wiki: Chèvre Cheese Making Recipe article, just updated it with correct pH range.

On firmness, Chevre is a primarily lactic acid coagulated cheese, primarily as only a small amount of rennet is used, way less than for rennet coagulated normally hard cheeses. There's some info on the different types of milk coagulation in our Wiki: Coagulation article and a couple of pictures of the lactic acid curd before draining, as you can sort of see it is a very soft curd that almost shatters when you go to draining versus rennet coagulated curd which while still soft is way harder. As someone posted in that other thread in my link above, it is yogurt consistency.

I wouldn't increase the rennet amount or time, if correct pH/consistency I would go ahead to draining phase.

[iratherfly]

How warm was your milk? In the summer go at 68°F to 72°F range, no more.  Incubate it longer at low temperature if it acidifies too quickly.  This could also be a sign of too much starter culture or a pathogenic bacteria that acidifies the milk faster than your starter culture.

The other thing to remember is that there is a pH change curve and it slows down at the 4.5-4.7 stage and no longer sharply go down so if that happens again, try cooling your vat to keep it at 4.6 for the rest of your 24 hours so that the enzymes can do their job.

Another reason for lack of firmness could be lack of Calcium - did you add a proper amount of Calcium Chloride? (unless this is raw milk you would need to add some)

Lastly about your rennet question; do not add any rennet.  Traditionally this is a lactic cheese that needs no rennet at all but with modern cultures and production schedules the natural lactic coagulation is being augmented with a little bit of rennet (½ to ¼ the normal amount you would use in rennet-coagulated cheese, about 3-4 drops per gallon).  Adding excessive rennet would affect the curd ability to drain properly and may cause final aged cheese to have a bitter after-taste.

[george13]

Thank you very much, your explanation is very good and you have provided some noteworthy points.  I have never added any CaCl to any of my cheeses, perhaps it is time.  The temperature I am sure contributes to the greater bacterial activity which produces acid faster than usual.  I need to devise a method of keeping the temperature in check.  My culture dosages are okay.  I also use very, very little rennet.
Thanks again to all who have provided info on this topic, I guess I'll try again when I have collected 6 gallons of milk, in the mean time, my pigs love the overcooked chevre.

[iratherfly]

Yes, once you get the hang of these there is very little error margin, they are fun and easy to make and everyone loves them.

Milk is really good about keeping temperature because unlike water it is highly dense. Generally speaking in the winter you start it with higher temperature that kicks off the bacteria (72°F-77°F) and let it rest in room temperature. Assuming that the room temp is lower than summer, the milk will stabilize at a lower temperature a few hours through and be ready at 24 hour.  In the summer the room temp is higher so start it at lower temp (68°F-72°F) and within a few hours it will warm up gently to room temp and get to about the same point at the 24th hour.

Calcium is a real necessity if the milk has been pasteurized.  (or, in early spring, when goats' milk is low on calcium).

More importantly it is easy to recognize when the semi-lactic goat's milk curd is at the correct acidity range for draining (could reach this point any time between the 12th and 48th hour). Here's how you know (forget the pH meter) 1). The curd will form into a single mass and separate from the sides of the vat 2). cracks will begin to appear on the curd mass (sometimes it may break into 2-3 "continents" if the cracks are really deep) 3). the curd mass will be covered by approx ½" of whey.  That's all there's to it. No need for pH meter to get this right.  Try it with a small 1 gallon batch and see that it just works.

[Cheese Head]

iratherfly, good point, in our Wiki: Coagulation article there are two pictures of mostly lactic coagulated milk just before draining, exactly as you said, one pulled away from walls the other cracking the middle.

[iratherfly]

Any luck yet?

[smilingcalico]

I believe if it's cracked, it's already past the 4.6 pH.  I learned that at a cheese guild meeting.  The solid curd mass and pulling away from the walls however are good indicators.  If you carefully vat pasteurize your milk at 145° for 30 minutes as prescribed, you shouldn't need calcium chloride.  Other forms of pasteurization are a different story.  Iratherfly gives good advice on temperature, but I'll season it a bit by saying you'll need to adjust temperature according to your local weather.  For instance in Oregon in the middle of winter (or much of the year) we'd start our milk at 84° and by morning find the vat at 77°.  I haven't checked your location, George, so I don't know if your deep south and hot, or far north and frigid.  Define a starting point and play around from there.  If you can be flexible and ladle the curd when it tells you it's ready, then you can save a few trial and error batches and continue making adjustments.

[linuxboy]

I believe if it's cracked, it's already past the 4.6 pH.  I learned that at a cheese guild meeting. 

Not true, whoever told you this was probably using anecdotal evidence. I can create several scenarios where the crack stage happens at 4.9 or even higher. But, it is good guidance, even if the pH absolute is wrong. Because if you use a classic lactic or semi-lactic technology, then what you're looking for is the proper aggregation of micelles. I wish I could whiteboard this for you to show what it looks like under the microscope. But the point is that you want nicely linked micelles, instead of underacidified, when the curd is weak, or overacidified, when the curd begins to aggregate into these large globs. The globs come out as a gritty, chalky sort of effect. Like a bad chevre that is not smooth... a clear technical fault. Anyway, when the crack stage happens, it's often a great indicator that this intermediate stage of micelle aggregation has been reached, and this is absolutely the appropriate time when to cut or ladle. Now, if your pH at this point is at the wrong range.. say it is below 4.5 or above 4.8, then there will very likely be textural defects, and at this point, the make process/ingredients/controls like temp need to be adjusted for all of it to work together.

It's kind of hard to be so absolute with lactic and semi-lactic types. They are actually some of the hardest cheeses to make because timing and feeling the curd are everything. You're messing around with degree of micelle bonding and rate of calcium bond degradation. It's why I often advocate the cheater approach of dumping in a tiny little rennet and culture together, and then cutting/ladling when the right pH has been reached. In this case, it's more foolproof that regardless of variations, the end product will be fairly consistent. The other approach is the classic, French long-set technique (culture to 6.0-6.2, add 2-5(depends on preference, can even do less) ml/100 lbs rennet, cut/ladle at 4.6-4.7 regardless of curd behavior)

[george13]

Thanks to all for your detailed explanations.  I am in upstate Ny so the summers do run somewhat hot and humid at times with cooling trends in the evening and early AM. My last batch was a sucess of pure lactic coagulation, simply because I monitored the product at various intervals without fail.  During the day, ambient temperature was around 80F, so I began early enough, set it at 70-72F, and let it sit in the room.  Twelve hours later, I was at pH 4.8, and three hours after that, at 4.58, with product temperature of 78F, at which point I ladled into my molds. 
I guess my next question regarding draining and pH is, how much more pH drop is acceptable once in the molding stage, i.e. what should my ph at time of final stage, packaging or consumption be, should I intervene with salt at a certain point?  My current MO is to salt one side after in the molds for about an hour, and flip the next day(7 hours later or so) and salt the other side. 7 hours later, refrigerate.
Thanks again

[smilingcalico]

Well, I got that tidbit of I info from the cheesemakers at Cypress Grove.  I'll have to see if I can find the packaging pH in my notes somewhere.  I know it was mentioned in the discussion.  I'll let lb or iratherfly give better detailed answers.

[linuxboy]

Packaging pH ranges 4.4-4.6. The theoretical drop cannot go far below that when using only meso culture. It will stabilize there naturally. If it doesn't, something is off.

From Cypress Grove, that is absolutely the appropriate guidance, because they are using a classic technique and technology, much like the one I explained in the post. It's appropriate because that is how goat milk behaves, and that is the pH behavior when making classic chevre. But note, other milks behave differently, and sometimes one has to adjust on the fly to achieve a high quality product, even when the pH is showing that one needs to take an action. Trying to differentiate between absolute science based on coagulation rheology vs anecdotal (good) guidance based on a proven recipe.