Anything with less gluten requires more lift, in general. Because the cornmeal itself doesn't rise, the wheat flour needs to do far more work. If one wants a lighter bread with a higher cornmeal content (or is making it GF entirely), egg whites beaten until they hold peaks, then gently folded in at the last, are useful. I am very used to the soured milk as I grew up with it. :)

The hot breakfast is a rather happy childhood memory for me. We didn't have a lot of money but it's hard to feel sorry for one's self with something so tasty to eat before school.