I was making a mozzarella cheese. I over heated my milk but everything was put it, citric acid, rennet. I was only supposed to heat it to 89*F and I heated it to 115 by accident. I let it set for 30 min like the instructions said. At the end of the 30 min. the curd didn't separate. It looked like it may have curdled a little bit. I poured it in a cheese cloth squeezed out liquid and covered it for about 50 hours in a dark place. Is this going to be good???
I'd suggest next time just letting the milk cool back down to 90 degrees again. You can have lots of problems trying things at higher temperatures.
Too much heat can deactivate the rennet -- that might be what happened. That said, a great many of us on this forum have had poor success with the so-called 30-minute mozzarella (ie, made with citric acid) -- even with the "right" temps, I've had the result come out more like ricotta than like moz. Also, the type of milk makes a big difference -- make sure you are not using ultra-pasteurized milk. That is guaranteed not to work at all. :(