Oven spring

Oven spring is the burst of rise that happens the moment dough hits high heat, before the crust has had time to set and firm up. It is the gas built up during fermentation suddenly expanding as the temperature climbs, and it is what turns a flat disc of dough into a pizza with real height at the rim.

How much oven spring you get depends on several things working together: how much gas the dough produced during fermentation, how extensible and strong the gluten network is, and how hot and fast the oven itself is. A very hot oven pushes gas to expand quickly before the surface hardens, which is a big part of why high heat ovens produce such a dramatic cornicione compared to slower home ovens.

Shaping technique affects this too, since pressing out all the gas bubbles when stretching removes the very thing meant to expand later. A common mistake is degassing the dough too aggressively by hand or with a rolling pin, or baking at too low a temperature, both of which leave the rim flat and dense instead of tall and airy.