This is totally off topic but your avatar is one of the cutest things I've ever seen.
That little one is such a cutie.
That, Dave, is my youngest son, who had just been sprung raiding my cave. He was very sheepishly handing it back to me, and I just couldn't resist taking a photo. And when he is not getting into mischief, yes he is a cutie.
Chili, no I can't tell you when the pH changed, and I was thinking the same thing. Was it the salting, or was it the aging that caused the change.
I use the long method when making mozz, so mine doesn't have any citric acid in it. I (probably stupidly) have always thought that that was the cheats way of doing it, and am determined to understand how this cheese works.