All good stories start with a group of friends, a relaxed conversation and a great question. In the case of this study, it all started with a group of physicists, a traditional Roman pizza and a question: how did you prepare it to be so good? This question led Andrey Varlamov, a Russian researcher who landed at the Consiglio Nazionale delle Ricerche (CRN) in Rome, and Andreas Glatz, a German physicist from the Argonne National Laboratory in the United States, to begin their particular study on the subject.
And on this journey, you and I can’t do without such a thing as a infrared thermometer for pizza oven.
To find a scientific answer to the secret of the perfect pizza, the physicists began their research by consulting the leading experts in the field: the Italians. And that’s when they learned that the first rule in finding an authentic Italian pizzeria was to look for one with a traditional stone oven. A resource that, according to the sources consulted, is a sign of quality of which the pizzerias are proud.
The secret of the experts
The next step for Varlamov and Glatz was to go directly to the pizzaioli, the artisans behind the gastronomic preparations that had so impressed them. They explained to the researchers step by step how the pizzas were prepared, from the making of the dough, through the ingredients used and the traditional cooking methods. This informal talk ended with a tip that would end up providing the key to the research: “Whenever you go to eat a pizza, go either before eight o’clock in the evening or after ten o’clock at night, when the pizzeria is half empty”.
As the Roman pizzaiolos Antonio and Vincenzo explained, the key to a perfect pizza was the temperature of the oven, a factor which determined the optimum cooking of the product. In the case of the Roman pizza, the oven had to be between 325 and 330 degrees centigrade to bake a pizza in two minutes, which meant that between 50 and 60 pizzas could be prepared per hour. But what happens when the demand for the product grows at peak times? In these cases, the pizzaiolos had to raise the temperature of the oven to 390°C in order to get the pizzas out in 50 seconds.
As the pizza makers explained, when the temperature of the stone oven was increased, the result was not exactly the same: the base and the crust of the pizza were slightly overbaked (even burning a little) and the tomatoes lacked a touch of cooking. In other words, with the change in temperature you could get a good pizza, but not a perfect one.
And it is precisely at this point in history that researchers began to explore the scientific basis behind these extraordinary pizzas they had tasted. An approach that, according to Varlamov and Glatz, would not be surprising if we consider that “physical principles are involved in almost every aspect of cooking”.
The thermodynamics of pizzas
Based on this premise, the study was based on an analysis of the pizza baking process, explaining how the use of a traditional stone or electric oven directly influenced the result of the pizza. In other words, a study of the thermodynamic principles involved in the baking of the product.
In order to analyse the thermodynamic principles involved in baking a perfect pizza, the researchers had to take into account different variables. From the thickness of the dough, to the amount of water (released by the mozzarella, for example) that evaporated during the process, to the impact of the ingredients on the final result. A task that would surely lead physicists to taste more than one sample of the research.
After countless calculations, detailed one by one in the study, Varlamov and Glatz managed to unravel the secret best kept by Italian pizzaiolos: temperature. In this respect, the physicists demonstrated that the key to achieving a perfect pizza is to find the balance between the heat released by the base of the oven and the radiant heat that is diffused through it. In other words, a magic formula that would allow the product to be cooked in an optimal way.
This balance would only be possible through the traditional stone ovens that authentic Italian pizzerias have, through which it is possible to achieve a perfect proportion between the heat provided by the stone base and that which is diffused inside it. On the other hand, in the case of electric ovens, the internal radiation was reduced by half, so the result lacked that plus which provides perfect cooking.
According to the researchers’ comments to the ‘Cosmos Magazine’, their next line of study could be the analysis of the principles on which the Italian chefs base themselves for the elaboration of the handmade pasta or the secret of the ristretto coffee. These are researches developed for the love of art, good food and, of course, science.