Mozzarella not stretching?

Hi, Cheese lovers

If you have the above problem I would recommend that you taste the milk first to see if you can detect something that way.  If the milk is not very sweet – chances are that water was added.   After doing a freezing point to eliminate that possibility, I would do solids, meaning fat and protein in this case. 

I would also do a phosphatase test to see if the milk was not pasteurized previously, because that would denature the protein so that it will not stretch on a second heating.   You might have pasteurized at too high a temperature yourself as well.

The milk could have a high SCC(somatic cell count) which is an indication of mastitis and this would lower the casein protein in the milk, which would lead to lower yields of cheese and slower, weaker setting of the curd.

Kind regards,

Leon the Milkman