So I worked my first eight hour shift today, and I had some difficulties, learned some interesting things, and in general came home smiling. The two main things that I learned deal with double hydration and venting an oven. When I was first shown oven venting, my eyes were pretty glazed over; I'd never heard of venting, and pretty much didn't know what it was, why you might do it, and in general was confused. A few days later (today, as it were) it was explained to me. Venting is, as its definition implies, removing air, or things in the air, from a space. You vent an oven at the very end of the bake, in order to remove steam and ensure that a good crust forms. But more then that, venting ensures that your crust will last, and stay long past its time immediately out of the oven.
Venting is the key to creating crusty breads.
We baked off baguettes today, but we also baked off some baguette dough cut for sandwiches, and these didn't get vented. The reason being rolls aren't supposed to be hard and crusty, but rather softer and easier to take a bite out of when you're enjoying a sandwich. If you don't vent, the moisture from within the crumb will move into the crust, softening it (diffusion!), but if you do vent, there is less moisture within the crumb to allow this. The moisture gets baked off during the vent period and is carried out of the oven. When I finished my shift, I walked out to my car and I said aloud, "well, I learned something today". The only thing left to determine is whether venting can be done in the home baking environment, which it may or may not be able to.
Secondly, double hydration. I personally have never been exposed to such a technique, or at least not by this name. You mix a stiff dough, then when the gluten is already formed, you mix in water to complete a high hydration. The dough is extremely slack and gets several folds to strengthen the dough. Now that I think about it, it is identical to making brioche or certain types of foccacia where you mix the dough to develop the gluten, then knead in butter or olive oil to enrich the dough with all the qualities large amounts of fat contribute. Additionally there is no shortening of the gluten that occurs when mixing large amounts of fat with wheat flour. I'm not really that blown away by double hydration, but its an interesting way to hydrate dough, and its amazing how similar ciabatta is to making foccacia, its just a different ingredient is being kneaded in.