In order to eat a pizza, he posted a fluid physics paper

Italy, Naples, the birthplace of pizza. In this cities with a population of less than 1 million, more than 240 restaurants that can make pizza can be searched online.

Unfortunately, in the "City of Pizza", Ernesto Di Maio, an associate professor at a local university, did not have this blessing -because he was severely allergic to the yeast of Pizza. The yeast in pizza or bread will make him grow rash and lumps.

Ernesto Di Ma Yue 丨 Twitter/@STEN8_

This is a bit embarrassing. If you do n’t eat pizza in Naples, others will ask him: Do you not like pizza? Why eat pasta? strangeness.

The classic method of pizza can be traced back to the 3rd century BC. In short, walk in three steps: painted tomato sauce in fermented noodles, sprinkled cheese and ingredients, and baked in the oven.

If you want to make a successful pizza, the basic condition is that you have to have an excellent dough; for a piece of dough, in addition to the raw materials such as flour, water, salt, the most critical ingredient is yeast.

Pizza dough 丨 pixabay

Yeasts are microorganisms. They eat starch and sugar in the dough, and then produce carbon dioxide (some people describe this process as yeast "snoring"). These carbon dioxide will be trapped, forming a small pores in the dough to swell the dough. Then, when the chef bakes the pizza, these gas will be kicked out, leaving a lot of holes in the cake to make the pizza noodle cake fluffy.

Fermentation requires just right. Insufficient fermentation will make the dough smaller and hard; the fermented dough will be sticky and sour. Moreover, yeast fermentation is a very slow process, which may take several hours.

In terms of "eating", human wisdom is infinite.

Many methods do not need yeast to make dough are constantly emerging. For example, mixed use of baking soda and lemon juice can also produce a fermented effect.

However, these other ways of justification cannot shake the status of the "yeast" in the hearts of the noodle cake masters. After all, the "yeast" as an important raw material for pizza was specifically included in the "Naples Pizza Paking Dang" by the European Commission.

Appendix: How to make a "abide by the law" Naples pizza dough

The European Commission has introduced the detailed specifications of the "Naples Pizza Dang" (NO 97/2010). The main steps are as follows:

1. Pour 60ml of water into the kneading machine (5L) container (the water temperature is 66 ° C-room temperature-raw material temperature);

2. Add 2.5g sea salt and stir manually;

3. Add 10 grams of flour and 0.15 grams of yeast, and start the kneading machine at a speed of 60rpm;

4. During the mixing process, gradually add additional 90 grams of flour within 8 minutes;

5. Run the noodle machine for 15 minutes. During the period, the temperature measurement of the dough is within the range of 24 ± 2 ° C;

6. Storage of the obtained dough at 25 ± 2 ° C temperature and the relative humidity of 75% are used for the wake -up stage, and humidity control is achieved by using saturated sodium chloride solution.

This also means that as a person who is allergic to yeast, it is impossible for Di Malo to eat pizza.

Life is like this.

Until one day, the doctoral student in his laboratory, a young man named Paolo Iaccarino, revealed that he was a doctoral student in material studies on his working day, and a pizza chef on the weekend. Do it. Thousands of pizza.

Left for Paul Icarino 丨 www.npr.org

A mentor who can't eat pizza meets a student who is particularly pizza. They want to be a pizza without yeast together.

Di Malo's proposal has also been related to the research he has been doing. Specifically, he is committed to finding a way to make polyurethane foam in recent years.

Polyurethane is a common polymer material in life. It is often used to make various foam or sponge. For example, many running shoes soles are polyurethane. Therefore, letting polyurethane foam is a common demand in contemporary chemical technology.

The method developed by Di Malo is to put the raw materials in a "high -pressure cooker", and to quickly increase the polyurethane to produce small holes by rapid increased air pressure; then slowly reduce the pressure, which can continue to expand these small holes. By regulating the pressure and pressure -keeping time, a variety of rich holes can be formed inside the material, so that polyurethane foam is successfully made.

The method developed by Di Macau can create different holes in polyurethane 丨 references [1]

It is also a hole, and the "pressure method" is useful for polyurethane. Is it possible to use the opposite dough?

After all, in the view of Di Malo, dough is just a substance that is "highly non -Newton, time -related, strain -related and viscous". In the theory of streaming, dough and polyurethane have the same magic.

Studies were officially launched.

For rigorous, they need to make a perfect dough first.

First of all, they use the superior raw materials for dough, including wheat flour produced in Naples, iodine salt from Rivego, and preferred yeasts from Palmat.

Subsequently, Icarino strictly made dough in accordance with the European Union's norms.

They also invited a chemical engineer to carefully measure the physical properties of the dough so as to copy them as much as possible in the non -yeast version. After reference, they used the same process to make new dough, but this time, they did not add yeast. Instead, they are going to "inflatable" directly to the dough through high pressure.

But the problem comes: no ready -made oven can provide the air pressure they need.

If you want to be good, you must first benefit your instrument. In order to find the right equipment, they also spent their strength and finally found a steriler. This kind of device is to kill bacteria with high temperature and high pressure. Although the size is small, it can be used to make "inflatable dough". Subsequently, they transformed the sterilizer and installed a sensor that could more accurately measure temperature and air pressure.

With the right equipment, they put the kneaded unparallia dough (made of flour, water and salt) into this high -pressure device, and then constantly debug various pressure parameters, temperatures and time to observe the changes in the dough. Essence It even cut the finished product of the dough carefully to count the size and quantity of the dense pores on the horizontal section.

In high -pressure containers, holes appear in the dough 丨 reference [2]

After a detailed experimental comparison of Di Macar, and combined with their rich theoretical knowledge of the flowing academic theory, the following conclusions are finally concluded: "Pressure Injecting" such physical methods and "yeast fermentation" biology Methods can be used to make Naples pizza.

However, these two methods have different mechanisms to swell the dough, and there will be some differences in details.

To put it simply, in the dough with yeast, the diffusion of yeast generated gas is relatively balanced with the pressure inside the dough, and the size of the pores generated is relatively uniform; in the method of Di Malo The pores produced are also uneven.

The pizza dough made by Di Macao 丨 References [3]

Even so, after roasting, the texture and taste of these two types of pizza are very close. And the non -yeast pizza does not need to wait for the fermentation process, saving time.

Subsequently, they published the research in the scientific journal "Physics of Fluids".

However, for researchers, this research still has a slight regret: because the high -pressure sterilizer at hand is small, the pizza made is only 0.4 inches, which is so large. Icarino, a chef student of Di Macao, also said that their works are not suitable for ordinary pizza enthusiasts.

Therefore, their next plan is to find a large high -pressure kettle and strive to make a 10 -inch pizza.

Perhaps ordinary restaurants are not ready, and use such a "cooking" device that requires a few centimeters of thick steel plates as protective cases.

From the pizza shop to the laboratory, in this "pizza without yeast", there is inspiration of interdisciplinary inspiration, in -depth physical chemical analysis, fine renovation of equipment, and a series of temperature, air pressure, time and other series of. Regulation of complex parameters.

Di Macao led the research team to do all this--

In order to make (people who are allergic to yeast) eat a pizza.

references

[1] Brondi, C., DI CAPRIO, M. R., SCHERILLO, G., DI MAIO, E., MOSCIATTI, T., Cavalca, S., ... IanNACE, S. (2019). Thermosting polyums by Physical blowing agents: Chasing the synthesis reaction with the presenture.the journal of supercritical flows, 154, 104630.

[2] Avallone, P. R., IACCARINO, P., Grizzuti, N., Pasquino, R. Mai, E. (2022). Rheology-Driven Design of Pizza Gas Foaming.physics of Fluids, 34 (3), 033109, 033109, 033109, 0331099, 0331099, 0331099, 0331099, 0331099, 0331099, 0331099, 0331099, 0331099, 0331099, 0331099, 0331099, 0331099, 0331099, 0331099, 0331099, 0331099, 0331099, 0331099, 0331099, 0331099, 0331099, 0331099, 0331099, 0331099, 0331099, 033109, Then, then, then

[3]Italian scientists hacked pizza physics to make dough without yeast, Ari Daniel, 2022, https://www.npr.org/sections/health-shots/2022/03/22/1087961262/roll-over-sourdough-italian -Scients-Develop-A-New-Rise-Pizza-Crust

[4] Commission regulation (EU). (2010) "Entering a name in the register of tractional spiecilities guarenteed, [Pizza Napoletana (TSG)]," OFF. J. Eur. Union34, 7–16.

Edit: malt Yang

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