Right off the bat - I'm an embarrassingly bad baker. I have a hard time following a recipe without understanding exactly why I'm doing what I'm doing.
So one little question that's been nagging me: what does punching down dough after the first rise accomplish? What is the exact difference to the end product from if you hadn't punched down the dough?
It would seem that you're letting gasses out of the dough, which one would think would lead to a denser bread. But I see it in recipes to make very light airy breads frequently. It's not that I'm doubting centuries of technique. I just want to know what is physically happening and why some dough recipes ask that you punch down the dough while others do not. McGee has failed me on this one (or else just hid the explanation well).