Question of make cheddar cheese from raw goat's milk

[Chung]

Hi everyone,
I have a problem...

Recently, I have tried to make cheddar cheese from raw goat's milk .
I don't know what did I do wrong...  
Because the milk won't curdle.


↓  My recipe  ↓
Step 1:  After milking, hold the milk for 3 hours before pasteurize.

Step 2:  Pasteurize 5~6 liter of raw goat's milk.  (Heat to 145~147℉ for 30 min)

Step 3:  After 30 min , cool my milk to 80℉.

Step 4:  Heat to 85℉ , add half the packet of Item # C101 culture stir and let set for 50 min.

Step 5:  Add the rennet stir 1 min and let set at 85℉ for 1 hour
( use 1/4 rennet tablet + 60ml non-chlorinated water )

After 1hour and more time , I found ...
The state of goat's milk still like liquid..  The whole of milk has not curd.


Could you tell me what did I do wrong ?

Is there a possibility that the raw milk needs to quickly use after milking and don't pasteurize?

(My English is a little weak, please don't mind.)

Thank you very much！

[awakephd]

Chung, welcome to the forum! I am sorry to hear about the problem you had with the milk setting, but this is a good place to get some answers. I'll start with a couple of ideas, and hopefully others will add in anything I've missed.

First off, I'm not sure that you did anything wrong. The one possibility would be waiting to pasteurize, but at most that would have allowed some of the naturally occurring bacteria to multiply, lowering the pH (raising the acid) - which is what the culture you added will also do. Rennet actually works better with lower pH than with higher ... at least, it works better at, say, 6.5 than at 6.7. But I don't know if there is a point at which it can get too acidic and not work - hopefully someone else can chime in on this.

The main thing I would be thinking about would be the rennet you used. Can you say more about the tablets you are using? I've never used tablets; I've only used liquid rennet, so I don't have first-hand knowledge, but I've read that there are some tablets that are called rennet which actually have very little of the necessary enzyme. (There's a name for these, but I can't remember what it is ...) Of course, even if you verify that the rennet is the correct type, you might have a bad batch.

The only other thing that I can think of at this point is to ask whether you disturbed the milk or added any heat to it during the rennet phase? Stirring for 1 minute is probably more than you need for that small a quantity of milk, but it shouldn't have been too much. However, if you stirred or agitated the milk after that, it could cause problems. Likewise, if you added any heat at this stage, it can cause problems.

[Bernardsmith]

A complete novice here but I agree about the possibility that the rennet is at the heart of the problem. Some rennet is made for a dish called junket and I think such tablets have very little of the enzymes you need to set the milk. Also if you dissolved even appropriate rennet in water but did not add this to the milk almost immediately then my understanding is that the rennet is no longer effective (does it denature? I don't know) . The other possibility is that you misread the temperature at which you pasteurized the milk. If you add too much heat you will prevent the calcium from bonding to make a firm curd. Is it possible that at least some of the milk was closer to the heat source and so was a good bit warmer than the milk where you sampled the temperature?

[Chung]

Thanks for the reply,

I have tried twice to this recipe.

At the first time, I used animal liquid rennet. (3/8 tsp + 60ml non-chlorinated water )
A second time, I used rennet tablet. (1/4 rennet tablet + 60ml non-chlorinated water )
Both state the same..

I bought the rennet on Amazon :
1. Tablet Vegetable Rennet (QSO+ Rennet Tablets)
2. Liquid Animal Rennet

I am sure that it is not a bad batch, because it has success to curd with HTST cow's milk.

I just added the rennet, gently stir 1 min and let set at 85℉ for 1 hour.
And I did not disturbed the milk or add any heat to it during the rennet phase.

BTW, I dissolved even appropriate rennet in water and add this to the milk almost immediately.

It`s really a very puzzling problem...

[Chung]

Is there a possibility that I needs to heat my raw milk to a specified temperature after milking, then cooling it as quickly as possible to rapidly and refrigerate ? 

Or... 

Do not pasteurize the raw milk , just milking it and as quickly as possible to refrigerate before cheesemaking?

[Gregore]

Did you let it sit overnight ?

If so was there curd then? , did you taste it , was it  tangy ?

My thinking is that your culture is dead , this is far more likely than you rennet not working at all .

You could try not adding any culture to the fresh  raw goat milk and also adding about 4 drops  rennet per gallon  let sit. At 70f for 24 to 48 hrs . You should have curd , after draining and rolling up into a log you should have. Chèvre .

[Chung]

Oh.. I did not let it sit overnight.   
I will try again next time.

Is there a possibility that I needs to cool it as quickly as possible to 40℉ and refrigerate before cheesemaking? 

Thank you everyone. Thank you very much.

[AnnDee]

I think you will get better set curd if you add cacl to your goat's milk. Goat's milk is normally higher in fat content and naturally homogenised so in my experience you get better firmer curd if cacl is added.

[Gregore]

 Cooling  to making temp as quickly as possible yes , less chance for contamination . But not essential to good cheese .

If you chose to pasteurize then it is best done straight away , cooling to réfrigération temps is just one more thing that lessen milk quality for cheese making .  And each day that it is cold lessens quality more.

You should be able to take milk right from the goat bring it in the house or cheese making room add culture ,add rennet  and make cheese .

If you trust the cleanness of the milk this is what I would do . Fresh raw goats milk cheese , yum.

Keep in mind that goats milk cheese acidifiés for 24 to 48 hrs and gets down to below 4.4 ph ( very tart taste) this kills most dangerous pathogens.

[Sweet Leaves Farm]

Pasteurizing the milk doesn't help with curd set. If your milk is tested clean and you are aging the cheese, you will get a much firmer set with raw milk. Be sure to use fresh starter culture and liquid rennet. Also test your thermometer to make sure its not giving a false reading. A pH meter would really help with knowing wether you are hitting the correct acidity. Let us know how it goes next time!

[Chung]

Thank you for all your assistance.

I will try again and check the pH values of goat's milk.

What does the best pH values of goat's milk before I add the rennet ?

[Gregore]

The ph changes through out the year and with the health of the animal .

But you should have a .05 to .1 drop after adding culture , before you add your rennet. This lets You know  the culture has woken up and started to reproduce .

Remember the probe on the ph meter needs to be at milk temp to give a  stable  reading . This can take up to a minute or more during which you can see the ph dropping as the temp read out climbs up to milk temp  when the temp read out stops going up the ph reading is correct for that temp of milk.

[tashad]

Remember the probe on the ph meter needs to be at milk temp to give a  stable  reading . This can take up to a minute or more during which you can see the ph dropping as the temp read out climbs up to milk temp  when the temp read out stops going up the ph reading is correct for that temp of milk.

Thank you for this, Gregore!  I didn't know that.  I have noticed that it takes a lot longer for the pH meter to read the correct temp than to stop flashing and show a pH.  Perhaps my readings will make more sense if I wait long enough for it to read the correct temperature.

[Gregore]

Yes ph readings are temperature    sensitive so most come with a internal circuit that adjusts for temp. So until the temp of the fluid in the tip comes up to temp  of the milk then the reading can be off a little .  It's not much but it can throw you off if your waiting for that .05 drop

As i get farther into the make I tend to worry less about temp difference  effect  on the probe  because it is less of an issue to be off by .1

[Chung]

Hi guys,
Thank you for the information.

Today, I tested for my pasteurized goat's milk ph and the ph values is 7.01 .
(The pH tester have a internal circuit that adjusts for temp.)

Is this correct of goat's milk ph values before cheesemaking?


I also bought cow's milk in the store and the ph values are between 5.5~5.6 .
(The pasteurization of this cow's milk is HTST. )

Did my goat's milk of ph values too high ?
How to let the ph readings come down ?