I am going to start adding protein powder to my food to get away from drinking protein shakes (which I am beginning to loathe) so my question is, when you are making hot food like oatmeal or soup, do you add the protein powder at the beginning and cook it with the food, or at the end when the food is already hot? I added protein powder to yogurt yesterday without a problem, but that was cold. I haven't tried any in hot food yet.

You have to add it after it is done cooking. If you add it to temps over 140 degrees the texture starts to change and it begins to damage the proteins. So if you have the piping hot bowl of oatmeal you will have to weight until it cools to below 140

Thanks!