If you cannot do this, and must heat the milk directly, be sure to monitor it constantly, stirring all of the while. If you do not have a thermometer , 185ºf (85ºc) is the temperature at which milk starts to froth.
[header] How to make yogurt [title] Heat the milk to 185ºf (85ºc). [step] Using two large pots that fit inside one another, create a. This will prevent your milk from burning, and you should only have to stir it occasionally.