Coagulated, Rennet, Cow - No Curd Formation, Insufficient Rennet

[Matt]

Need your help guys.
Heated homogenised 5 litres of full fat milk to
90 degrees.
Added 5 ice cubes of manufactured culture solution.
Waited an hour.
Added diluted rennet, 5 drops in 50ml of water.
The problem being after 2 hours no sign of coagulation, still just like normal milk. Where am l going wrong? Should the milk smell sour after adding the culture, mine didn't. Was wondering if l need some new culture and that the milk is not acidifying?

[zenith1]

Hi Matt- what type of manufactured starter did you use? Was it the correct type for the temp range that you were working with. Also for 5 liters of milk you probably needed a little over 1/4 tsp of rennet. Also the milk should have a ice sweet smell to it as it ripens. It should not smell off or sour. After the ripening phase and the addition of the rennet you should certainly had flocculation by the one hour mark. Possible not enough rennet added. The addition of cacl at the rate of ~ 1/4 tsp per 2 gal will help give a firmer curd formation. Note that it will only help give a firmer curd and is only needed for processed milk. If something was not correct with another step in the process, adding cacl will do you no good. I would look at your starter first(correct type and amount), then the rennet(date and application rate)next.

[Cheese Head]

Matt, just to chime in, I've spent part of today updating three webpages on Coagulation, Rennets, and Coagulation Problems, still needs some work but better.

When Baby Chee asked if you used salt, I think he is asking if you added Calcium Chloride which helps in coagulation of pasteurized homogenized store bought milk.

Hope those pages help and as zenith1 says, some more details would help. While lower pH from an active starter culture helps coagulation, it is not required, you should be able to coagulate plain milk with just rennet.

If your batch is ongoing as we speak, then you have two choice with it, either proceed to use it for a primarily acid coagulated type cheese such as Neufchatel, or dilute and add more rennet.

[Sailor Con Queso]

5 drops is VERY little rennet. What kind of cheese are you trying to make?

[Alex]

The coagulant I am using is MAXIREN. Manufacturer's instruction is, 1 drop per 1 liter of milk.

[Matt]

Thanks guys, just been back to it after leaving it overnight. It had coagulated but not enough for a clean break. I am going to try again but use 1/4 tsp of rennet. Only used about 1/3 of that so that could be the problem. Going to try and get non homogenised milk as well, think that would help. I will get my Gouda in the end!!!

[Baby Chee]

I've gotten Gouda from homogenized milk, so it is possible.  Remember the addition of some salt, and get the rennet right, and you are probably fine.

All from homogenized milk.

[Sailor Con Queso]

Use Calcium Chloride NOT Sodium Chloride "salt". Calcium chloride restores a calcium balance to pasteurized milk. Salt (Sodium chloride) will inhibit bacterial growth and affect whey content in your curds.

Maxren is a pure chymosin vegetarian coagulant, derived from a genetically modified yeast, Kluyveromyces lactis. Are you trying to make vegan cheese?

One drop per liter doesn't sound right.

[Alex]

Use Calcium Chloride NOT Sodium Chloride "salt". Calcium chloride restores a calcium balance to pasteurized milk. Salt (Sodium chloride) will inhibit bacterial growth and affect whey content in your curds.

Maxren is a pure chymosin vegetarian coagulant, derived from a genetically modified yeast, Kluyveromyces lactis. Are you trying to make vegan cheese?

One drop per liter doesn't sound right.

Sailor,

I am not sure, I think I use the Maxiren 600. I am not trying to make a vegetarian cheese, it comes out that I have to. Because of kosher matters in my country this is the type I can get handy. Again, 1 drop for 1 liter of milk. Only two years of cheese making with this stuff with the dosage mentioned, never failed.

[Sailor Con Queso]

Alex, Of course, I forgot that you need to be kosher. Maxren is 100%pure chymosin so it must be concentrated. I am still surprised that 1 drop will coagulate 1 litre. Obviously it's been working for you for 2 years.

I could be wrong, but I don't think that Maxren would get old and lose it's potency. So there must be something else going on.

A high pH might be the cause. A drop in pH is what causes Casein to lose electrons and start coagulating. I think you are using yogurt and buttermilk? A high pH could be because your culture didn't acidify. Do you test pH? I think you are using raw milk, so high pH can also come from late lactation milk.

[Cheese Head]

Matt, original poster:

• All I've almost ever used is store bought pasteurized homogenized cow's milk with minimal coagulation problems todate.
• What rennet type are you using that you didn't get a good curd set in normal time period?

[Alex]

Alex, Of course, I forgot that you need to be kosher. Maxren is 100%pure chymosin so it must be concentrated. I am still surprised that 1 drop will coagulate 1 litre. Obviously it's been working for you for 2 years.

I could be wrong, but I don't think that Maxren would get old and lose it's potency. So there must be something else going on.

A high pH might be the cause. A drop in pH is what causes Casein to lose electrons and start coagulating. I think you are using yogurt and buttermilk? A high pH could be because your culture didn't acidify. Do you test pH? I think you are using raw milk, so high pH can also come from late lactation milk.

Sailor,

I am not the one with the coagulation problems, it's Matt. About loosing potency of the Maxiren, you are wrong, it's shelf life is 12 months kept in the fridge (4-8 C), and yes, I am using buttermilk and yogurt as cultures with raw milk.
BTW, personally, I DO NOT NEED TO BE KOSHER and in everyday life I am not, but some things sold officially and publicly HAVE TO BE KOSHER.

[Matt]

Guys, second try and it worked! Used 3 litres of non homogenised and 2 of homogenised. 70 drops of rennet, just over a 1/4 tsp. Using vegetarian rennet, clean break in 2 hours. My Gouda is pressing overnight as l write. Will post some pics of the finished cheese. Thanks for all the advice.

[Sailor Con Queso]

Two hours is still a really long time.

[zenith1]

Matt- glad to hear that you narrowed the problem down to an insufficient quantity of rennet. At least that is easily fixed. The two hours to establish a clean break still seem excessive. Have you tried to using the spinning bowl method to determine the time of flocculation? I think that in my experience it works better than trying to determine a clean break.