I've just purchased a PH meter -- haven't used it yet. But I have been making some killer feta lately -- and I have found that if I drain it longer --I'm averaging 5-6 hours --it is drier and crumbles much better. I also turn it over midway through hangling to give it a better shape. Using store bought milk, I struggle with brining unless I use whey. In the case on my feta, I don't brine. I cut it (after letting it hang 5-6 hours), sprinkle with salt, let it sit, drain after 12 hours, turn it over, sprinkle with more salt, and let it sit another 12 hours. It sits on my counter uncovered until it feels dry and I proceed to the final step. i've tried putting it in the cave, in the brine, and this seems to be the method that works for me. My final step is marinating the feta in a seasoned olive/canola oil blend. Been using some garlic, pepper, etc in the blend. Once I marinate it, I let it sit for a few days in the fridge --turning the container from side to side every day to mix up the seasonings. The feta is fabulous. I can't make enough -- people at work have started asking me to make it on a regular basis and would eat everything that I make if I let them!
Hope that some little tidbit here helps you. I know that I have made great strides in the last several months taking bits and pieces of what I have learned here and mixing it to the situation at hand -- every bit of information helps in some way!