Two hours have passed, and your dough should be tripled in size. Turn it out onto a floured surface, and round it.
Flour a cheesecloth or linen and line a colander. Place rounded dough in, cover with foil and allow to double in size, 45 minutes.
In the meantime, place an empty pan onto the lower rack of your oven, and preheat the oven to 450F.