Cornicione

Cornicione is the Italian term for the puffed border that runs around the edge of a pizza, the part left free of sauce and toppings so it can rise on its own during baking. It is one of the most visible signs of how well a dough was made and baked.

The puff comes from gas trapped in the dough during fermentation expanding rapidly once it hits high heat, a reaction that happens fastest and most dramatically in very hot ovens. A well developed cornicione is light and full of irregular air pockets, with some charring across the surface rather than a dense, uniform crumb.

Judging a cornicione tells you a lot about the dough and the bake: an even, tall rim with scattered dark spots usually means good fermentation and enough oven heat, while a flat, dense rim points to underproofed dough, a dough that was handled too roughly, or an oven that never got hot enough. A common mistake is pressing or docking all the way to the edge of the dough, which flattens the very structure meant to puff.