wheat rolls

These are super easy and good! The only thing I'm not sure why it happened was after shaping the rolls and letting them sit for a second proof, I then applied an egg wash before baking them. After the wash, the surface started bubbling, as if the egg wash prompted air under the skin. I noticed it twice because I made 2 different batched in a week. Is there something I should know? I'll have to ask at school....