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Ah, crispy crust Italian-style pizza with perfectly cooked toppings and a moist fluffy dough. It’s hard to beat, and despite the simple ingredients, it’s also challenging to replicate at home.
The reason it’s so difficult, according to pizza aficionado Andreas Glatz, a professor in the Department of Physics at Northern Illinois University, has to do with some special ingredients—and we’re not talking about tomatoes, mozzarella cheese and extra virgin olive oil.
The key is the precise amount of thermal conductivity and radiation delivered by a wood-fired brick oven, according to Glatz and colleagues Andrey Varlamov, a professor at the University of Rome Tor Vergata, and Italian food anthropologist Sergio Grasso.
The trio conducted a study comparing the process of cooking pizzas in a brick oven versus a standard metallic oven common in most homes. Their findings, based on the principles of thermodynamics and proved in great mathematical detail, clearly show why a brick oven is indeed superior.
The wood-fired brick oven delivers the perfect balance of both radiant heat, needed to cook and evaporate water from the toppings, and heat transfer into the bottom of the pizza, via thermal conductivity from the bricks below.
Glatz says Varlamov came up with the idea for the pizza project as an educational lesson. The authors first talked to local pizzaiolos in Rome about the secrets of making pizza. It’s typically cooked for two minutes at 620 degrees in a wood-burning oven with a fire-brick bottom.
“We wanted to figure out why the high temperature and two minutes of cooking time were essential,” says Glatz, a Naperville resident who hails originally from Germany.
“If you put a pizza in a metal oven at the same temperature, you burn the dough right away,” he says. “This is because of the properties of the metal. And typically a metal oven can’t reach the temperatures of a wood-fired oven. So then you have to cook the pizza much longer, and it won’t have perfectly cooked toppings or the dough will be too dry.”
When the pizza is crowned with water-rich toppings such as eggplant and tomatoes, pizzaiolos are also known to use a trick at the end of the two-minute baking process. By elevating the pizza with a long spade for 30 seconds or more, they expose it to more heat irradiation to finish the toppings without burning the dough.
The study, which also discusses the origins of Italian-style pizza, is a far cry from the standard fare for Glatz and Varlamov, who typically collaborate on highly complex superconductivity research in Rome, Italy, and at Argonne National Laboratory in Lemont, Illinois.
As it turns out, the media gobbled it up.
The study was featured recently on the National Public Radio website and in Cosmos, a quarterly magazine that’s also online. It provides a good way to show how physics can be useful in everyday life.
“I don’t know if it’s the healthiest food, but it is delicious,” Glatz says.
He adds that there is, of course, more to a perfect pizza than the baking method. Local ingredients, dough preparation and the smoky flavor from the wood-burning oven also contribute to pizza bliss, but those factors were not analyzed.
The researchers specifically looked at Roman- and Neapolitan-style pizzas made famous in Italy. What’s often called deep-dish or Chicago-style pizza is another can of tomatoes entirely.
“It’s more pie than pizza,” Glatz says.
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Media Contact: Tom Parisi