How can kneading something create more gluten? Gluten is a protein. Can moving something around create more protein? I doubt it. So what is really happening? Are the gluten proteins bonding differently or tangling?
2 Answers
Yes, kneading develops gluten. Specifically, the gliadin and glutenin proteins in flour form gluten when mixed together with water. It's common, but inaccurate (and confusing I think) to refer to gliadin and glutenin as gluten.
For more about the chemistry of how gluten develops see the paragraph on 'bread products' in https://en.wikipedia.org/wiki/Gluten.
Hydration (adding water) is the main reason for the gluten development.
Kneading on the other hand, not only helps hydration by effectively mixing the contents but also causes cross-links of gluten webs forming, thus giving the dough (and eventually the baked product) the chewy texture.