Uneven coagulation in cream cheese and sour cream

[RenaissanceM]

I had my first attempt in making a light cream cheese and sour cream with a somewhat failed results. For the light cream cheese I used store bought homogenized milk 3.25% (past. around 78 deg Celsius) that had no additives. I added cultured buttermilk as per the recipe posted on this forum as well as few drops of rennet. I let it sit at room temp for 24 hours.  For the sour cream, I used table cream (18%) which I'm sure it's been Ultra pasteurized and had stabilizers and gums added. I also added the same buttermilk and few drops of rennet.

The result for both came out pretty much identical after 24 to 36hours at room temperature. The top 1 to 2 inches appeared to have a nice curd formation with nice clean edges when I scooped it for drainage (for the light cream cheese), however the deeper I went into the container the looser and stringier the curd was.

The cream cheese was a disaster after draining as the slimy and stringy part was not draining at all. The sour cream I stirred and placed in the fridge. The top firmed again however the deeper I went the stringer it was. Both of the curds smelled very nice and the sour cream was tasty even a week later so I'm not concerned about contamination.

Should have I left them outside a bit longer to develop? Is the type of milk used an important factor? Does adding any CaCl2 make a difference in these types of cheese seeing they're both pasteurized at a high temp and homogenized?

[MrsKK]

I don't use pasturized milk for making my cheeses, so don't have practical experiene to contribute, but I think that what is happening here is due to the cream being UHT.  I don't know the conversion for Celcius to Fahrenheit, so I'm not sure if your milk was UHT also or not.

Members usually have to try different milks until they find the brand that works best for them.  Those who use past/homog milk usually add CaCl for better curd formation and better yield as well.

Hang in there and keep on trying!

[linuxboy]

Commercially, cream is often double homogenized when making sour cream to get a very thick coagulation. Meaning you're trying to get to 100% as much adsorption as possible. Using UHT cream is fine for a lactic set.

Stringy means bacteria. What you have is contamination or poor buttermilk. Or uneven incorporation of the buttermilk into the cream.

[RenaissanceM]

Thanks for your replies. I will try again but this time will use meso culture as opposed to store bought buttermilk and note any difference. I'm pretty sure I incorporated the buttermilk enough.

The fact that the top surface was properly set is a bit puzzling, and then the gradual transition as it went deeper. The only thing that comes to my attention is perhaps the better availability of oxygen to the top surface. I had an air tight plastic film covering the container. From what I recall the meso and thermo cultures require some oxygen but not too much. Would I have better results if I didn't have an air tight cover on the milk as it develops?

[linuxboy]

The fact that the top surface was properly set is a bit puzzling, and then the gradual transition as it went deeper.

Cream rises, even when homogenized and stabilized with hydrocolloids. The top layer is likely thicker, and that's what you skimmed.

From what I recall the meso and thermo cultures require some oxygen but not too much.

No, they do not. lactic metabolism is anaerobic.

[RenaissanceM]

I see. It's still odd that after I stirred the sour cream (18% cream) after the 24hrs and placed it in the fridge the same phenomenon happened. I had the top set while the bottom remained loose. Nice to know. Thanks.

[linuxboy]

Bacterial strains also differ in their preference for flocculation areas. Some prefer the top, some the bottom. And some change their preference based on the temperature.

It could be a number of factors. I'd try different milk/cream, and/or different culture and see if that makes a difference.

[RenaissanceM]

That makes sense. I will try my DVI meso culture instead of the store bought buttermilk and note the difference. Thanks for your help.