Mozzarella 2 success then grand failure

[adnanpic2000]

Hi, I had two successful mozzarella success and a GRAND FAILURE.
I have RAW BUFFLAO milk access two time is used the same supplier and the PH of milk was 6 then 6.5 both were 1g.
The third time I got 5L milk and the PH was 5.7 and I was thinking I should use less citric acid, but decided not ; and the end PH was 3.5 DIASSTERRR.
So my question is if the milk PH is lower then 6.5 i should reduce the citric acid, but by how much. Also i am using yogurt as starter in all three attempts 1 OZ.
Or if there is a way to bring the PH of milk back around PH6.5.
Thanks

[Sweet Leaves Farm]

Oooohhh, raw buffalo milk! You must be using  a modified method, both starter and citric acid. Your yogurt could have more live culture in it, which would affect the amount of time it takes to drop pH. Or the raw milk has a few too many of its own bacteria, and got the process started before you received it. When my girls milk changes pH, I just gradually add the diluted acid a 1/4 tsp. and a time, until i reach the target pH. Anyone else have any ideas?

[Kern]

Hi, I had two successful mozzarella success and a GRAND FAILURE.
I have RAW BUFFLAO milk access two time is used the same supplier and the PH of milk was 6 then 6.5 both were 1g.
The third time I got 5L milk and the PH was 5.7 and I was thinking I should use less citric acid, but decided not ; and the end PH was 3.5 DIASSTERRR.
So my question is if the milk PH is lower then 6.5 i should reduce the citric acid, but by how much. Also i am using yogurt as starter in all three attempts 1 OZ.
Or if there is a way to bring the PH of milk back around PH6.5.

The pH scale is logarithmic.  That is a pH of 5.5 has about ten times as much acid as 6.5.  Likewise, 4.5 has ten times the acid as 5.5 and 100 times the acid as 6.5.  You can used this as a guide.  I'm surprised that unadulterated milk would vary from 6.5 to 5.7.  Assuming that it was indeed 5.7 then I'd cut the citric acid down by about 80-90% from a proper addition at 6.5.  You can always add more but you can't take any out.  The only way to change a lower to higher pH would be to add some alkaline material like sodium bicarbonate.  This would like screw up the taste of the final product.