How much total flour you use will depend on the humidity of your house and how you measure your flour. That's why you'll start with three cups of flour and gradually add more as needed. You want the dough to come together in a ball and mostly pull away from the sides of the bowl, so add more flour gradually until it does. This recipe is fairly forgiving; a little too much or too little flour will be just fine. Just be sure not to dump the entire four cups of flour in at the start or your may end up with tough garlic knots.