After one hour, stir the ingredients with a spoon. Make sure to get all the way to the bottom of the pan, so it doesn't burn. Meanwhile cook and dice your bacon. After the macaroni has cooked for 2-2.5 hours you should have a creamy mixture with little standing liquid. Add the bacon and give it another good stir. Taste and add salt as necessary. Sprinkle the bread crumb topping over the pan, and cook an additional 30 minutes, until bread crumb begins to brown and the liquid is bubbling up through the topping. The finished product should be creamy, but not runny.