[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. 
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.