Making Cajeta and the milk goes grainy?

[onebizebee]

when making Cajeta I must be doing something wrong. I am slowly heating up the milk not even to a boil. The milk gets thick and then goes grainy what is up with that? I have tried three times now. The milk goes thick even if I heat it past 170 crapity crap crap. Never have a problem with cow milk. Any ideas? No mastitis etc going on. I am currently using the milk for soap at the moment because the field onions are up plentiful at them moment. Ick!

[Alice In TX/MO]

It got too hot. I've had that happen when I almost boiled it.