To achieve its chewy, bubbly texture, our recipe for Pizza Bianca calls for 9 parts water to 10 parts flour—an almost 30 percent higher level of hydration than in most other pizza dough. Water aids the development of gluten, the network of crosslinked proteins that gives bread its internal structure and chew. Up to a point, the more water in the dough, the stronger and more elastic the gluten strands and the chewier the bread. These strands, in turn, help to support the air bubbles formed as the dough bakes, preventing them from bursting and creating an open, airy crust.
Source: Cooks Illustrated Published September 1, 2008.