How To Know If Yoghurt Is Pasturized HELP!! I Need This Recipe FAST! How Do You Make Yoghurt Without Using Culture Starters Or Yoghurt?

HELP!! I need this recipe FAST! how do you make yoghurt without using culture starters or yoghurt? - how to know if yoghurt is pasturized

I have lemon or lime, but I do not know how. If u have the complete recipe and method that will be much better. :)