Now that we know why we hold pizza the way we do, it's time to move on making a great pie. There are dozens of varieties. I'll stick with one I have some (perhaps too much) experience with - Neapolitan. A few other thin crust styles like New York (which has a higher fat content in the dough) will be somewhat similar, but deep dish and other types have dramatically different baking requirements.
Folklore and my experience suggests a brick oven does the best job. These are usually a set around 330°C (about 625°F). The cooking surface is brick with a large brick dome covering the space. Many of these use burn gas, but wood is sometimes used to impart a bit of a smokey flavor. Much more common are commercial steel electric or gas ovens. Chain pizza shops? I'm not a fan.
There are three heat transfer mechanisms: conduction, radiation, and convection. Conduction is heat transfer by direct contact between the oven and pizza bottom. Radiation is infrared energy that largely comes from the rest of the oven - the broiler element in your oven uses this trick. Finally convection is the transfer of heat from the oven to the pie by the air.
Convection turns out to play only a minor role so we'll skip it. Conduction is another matter. In our 330°C brick oven the interface between the pizza and brick is about 210°C (410°F).1 In about two minutes the bottom cooks nicely and the temperature at the top of a half centimeter thick pizza approaches the boiling temperature of water.
Most pizzerias use steel pizza ovens. Steel is a much better conductor of heat than brick. With the oven set at the same 330°C, the temperature at the bottom of the pizza is now much higher - about 300°C (570°F) and the bottom burns quickly. Dropping the steel oven's temperature to 230°C (445°F) will give you the good 210°C crust cooking temperature, but there's another problem - what about the top of the pie? For both brick and steel ovens we need to look at radiative heat transfer..
Infrared radiation from the 330°C brick walls quickly raises the temperature of the top of the pie to the boiling point of water allowing water in the cheese and toppings to evaporate so they can cook properly. For a simple Margherita pie two minutes gives a nearly perfect "balance" with everything cooked just right. The cooler 230°C steel oven has a much lower radiative heat transfer. So low the top of the pie doesn't reach boiling by the time the bottom cooks Cooking the top requires another 90 seconds or so leaving the crust overcooked.
You can partly get around these problems by adjusting the dough (New York style pies have a higher fat content), using a broiler element (some steel ovens have them) or physically lifting the pie from the oven floor with a wooden pizza spade for a minute or so. A good pizza cook with a brick oven will also use the spade on a Neapolitan pie if there are a extra toppings.
If you're lucky enough to visit a shop with a brick oven and good cook, try to go when they aren't busy. It is common to raise the temperature to at least 390°C during busy hours to increase throughput by turning around pies in about eighty seconds. These fast and hot pies are difficult to judge and frequently have slightly burned crusts. It's even harder if ask for anything more than the simplest pie.
You can get a ceramic or brick pizza stone if you want to back a pie a home. Set your oven as high as it will go and experiment - it will take more cooking time. I've tried with lackluster results .. I tend to wait and visit real pizzerias. Alternatively you can work on types of pizza that have very different cooking techniques.
__________
1 You can calculate this with a differential equation using the thermal properties of the brick and pizza. It gets a little messy and the 210° figure could be off by a couple of degrees, but it's in the right ballpark and that's a good temperature for baking the crust.
Comments