Thanks for the tips guys. Heating the curd in the reserved whey really makes sense when considering the ph, thanks Debi.
I didn't think that creme of tartar was the same thing as tartaric acid, it couldn't be that easy. Lennie, thanks for the lead on where to buy it.
How critical is the heating/melting temp?(170degrees F), or the cooking temp 108 degrees F)? I may have let the temp go up to as much as 113*F at that stage. Is that a fatal error?
Debi, I tried to salvage the last batch by heating/melting and stretching. The curd stayed grainy, absolutely would not stretch, and was rubbery. I hate to throw things away too, but this batch looked unsalvagable. I will certainly heat the curds in the whey next time. It seems that my problem is the ph issue.