Mozzarella dilemma

[Olga]

Hello, my name is Olga and I hope you can help me.
I have been making mozzarella for the past 4 months. I use thermophilic culture and microbial rennet. The milk I am getting from the neighboring dairy farm. It is Jersey cow`s milk and I remove half of the cream once it has settled. Most of my mozzarella has been of a good texture and quality, but I run into problems every now and then. I don`t know who to turn to regarding the following:   

1. What is the best pH for my specific milk in order to reach the best elasticity for forming and not over ripening the curds? 
I have read many recipes and the recommended pH ranges from 5.4 to 4.6. So you can understand my confusion. At the moment my curds stretch well at pH 5.3. according to pH meter, but I`d like to improve on this without adversely affecting the outcome of my mozzarella.
2. Starting to form balls at pH 5.3. according to my pH meter, normally goes well but on occasion the curd develops small lumps after about the fourth ball and a nice glossy finish is no longer achieved. Please give me your views on this problem.
3. What is the best way of checking the pH for mozzarella making?
I have 'Merk' pH indicator strips and a 'Milwaukee pH 600' meter. Their readings are always different from each other. If the meter shows pH 5.3, the strips show pH 4.7. These readings are taken from the whey. I realize that I should rely on the paper strips more than the meter, but if I start forming balls at their indicated pH of around pH 5.0. the curds would not stretch and were very rubbery.
I look forward to your help and opinions.

[Alison]

Hi Olga

Unfortunately you are probably going to have to experiment yourself to optimize your ideal pH, but I'd like to add some info that (I hope) could help you.
1. I have done Mozz with jersey milk and generally pH5.3 spins with success.
2. What is the temperature that you spin the mozz at? It may well be too low by the 4th ball, or the pH is dropping. Why don't you add all the curd to the hot whey/water at the beginning, nothing like >50degC to slow bacterial action....
3. My guess is that your pH meter needs a calibration - you will have to read the manual for that procedure, (and what solutions are required). Perhaps the probe itself damaged. Strips that have been "badly" stored can also read funny, so you may want to get a new batch.

Having said that, I just test a bit of curd in a cup of hot water - if it stretches, it's good to go (check out the "Washington cheese guild" site). I realise that it also requires experience to know when "stretch" has been achieved, but it's a fair test. I find that the freshest milk (unpasteurised) is the most forgiving of pH variations, even extremely low pH, so that may be a good place to start experimenting.

good luck
regards
Alison

[DeejayDebi]

This may sound odd but how is your water temperature by the 4th ball?