What is a prerequisite for curling the round salam "Peperoni" indispensable to pizza?

ByAlexis Gallisá

Although there are various kinds of popular toppings in pizza, one of the things absolutely indispensable is salami 's "pepperoni"Can be cited. It can be said that the flavor of Pepa Roni's meat juice that is burnt in a crispy and crispy surface, a unique shape curled upwards, and the peppers' gravy prawn in the curled "cup" is a must have as a flavor to define pizza However, why such pepperoni curls when baked and there are conditions for curling it well, blogs pursuing such things seriously are released.

The Food Lab: Why Does Pepperoni Curl? | Serious Eats
http://slice.seriouseats.com/archives/2012/12/the-pizza-lab-why-does-pepperoni-curl.html

I created a blogJ. Kenji López-Alt(Ms. Kenji), a specialized website on food "Serious EatsIn addition to managing a column about many foods, he seems to have extraordinary feelings against pizza. In writing a blog entry about Pizza Peperoni, it seems like a spirit of saying that "This is the most important thing in my career, no matter what in life", especially as shown in the following picture Kurutsu Curling and developing hot speech about pepperoni with juicy gravy in it.


People who ordered pizza at a shop or courier to see what they arrived may sometimes want Pepa Roni to be flat, but Kenji seems to be unforgivable. The pizza with pepperoni is filled halfway with the cheese melted curled pepperoni, it is indispensable to say that calicious burning condition and juicy gravy are indispensable.


Kenzi says about curled pepperoni "Grease chaliceI am using the expression ". This term meaning "Holy Grail of fat" was touched in the following work which was written in the English haiku contest about food held in 2005, Kenji said "It is beautiful so far, Have you ever seen something that struck the core? "

Crisp pepperoni

Edge curled from heat

A chalice of sweet, hot oil

(Translation)
Crispy pepperoni

Heated curled edge

Sweet, Holy Grail of hot fat

Mr. Kenzi, who sets a theory of pepperoni in a rather runaway manner, says "Pepperoni has a condition that causes curling essential"Thickness at cutting"When"Material of casing (film) of peperoniIt is said that he decided to make a hypothesis that it is important to verify it.

◆ Hypothesis 1: Thickness is important
Pepperoni curls when pizza is baked because the degree of burning changes between the upper surface exposed to the heat of the oven and the lower part where heat is blocked by the pizza dough and cheese, the shrinkage rate changes, and as a result Mr. Kenji thought that curl would occur, actually sliced ​​peperoni into various thicknesses, and examined what kind of difference would arise.


In the experiment, we measured the thickness precisely using a vernier caliper and seemed to use pepperoni cut into 8 thicknesses from 1.3 mm to 6.4 mm.


Pizza sauce on the dough, mozzarella cheese on top of the pizza dough, toppings of 8 pepperoni in the oven.


The result is like this. The level of "Cuppage (cup page: cup)" was influenced by the thickness of Peperoni, and it turned out that the thinner the cuppage level, the lower the level. Among them, it seems that pepperoni having a medium level of thickness was found to have generated cups most successfully.


From the experiment, Kenji judged that it is impossible to verify everything with only the thickness, although the cupping occurs if there is some thickness. Kenji thought that the cuppa was influenced by the difference in heat generated on both sides of peperoni decided to do another verification.


◆ consequences derived from hypothesis 1: orientation of heat source
Kenzi arranged six pieces of pepperoni sliced ​​to the thickness on the pan and added heat with fire from the bottom. Then, it turns out that both are curled downwards and a cup (cup) occurs. In addition to the "thickness" of hypothesis 1, it is said that "the direction of the heat source" is recognized as one of the factors causing cupping.


◆ Hypothesis 2: Casing material is important
Generally there are three casings (coatings) used for pepperoni, which use natural materials, artificial materials made from collagen, and no casing. Mr. Kenzi then ordered pepperoni, which consists of multiple material casings, from the acquaintance's vendor to verify what kind of difference will occur for each type.


As a result, it was found that pepperoni with collagen casing produces more crispness than natural one. This means that the heat shrinkage of the casing caused by heating varies depending on the material, and collagen type shrinks more strongly, so the peripheral part shrinks more than the center part, resulting in a large cup.

Mr. Kenji was trying to heat Peperoni while peeling off the casing, when he saw a certain tendency, it turned out that pepperoni without a casing curls in the same way. In other words, although the degree of cassette due to the difference in material of the casing is different, by cooking the meat material in the casing at the manufacturing stage, it became clear that Peperoni curls with its own work without the casing It is said.


Kenji was confused in this situation. Because it turned out that the casing considered to be the source of the curl generating force was not a necessary condition, it became necessary to find out another element in order to grasp the true mechanism. Next, Mr. Kenzi noted that "Fluid dynamics of stuffingIn other words, it is a hypothesis that the difference in density that occurs when filling (packing) the meat which is the material of pepperoni may act.

◆ Hypothesis 3: The Fluid Dynamics of Stuffing of Stuffing
Mr. Kenji, who was confused as above, asked meat experts for advice. Then, when stuffing fillings in natural material casing and collagen casing, it seems that they taught that casing extension method is different.

The following picture shows a piece of collagen material casing made of pepperoni cut longitudinally. Because the casing does not stretch too much, when pushing in the filling, a large force is applied to the center part of Peperoni, and as a result, a state with a high density remains so that it can be seen that a pattern is generated in the longitudinal direction.


In the case of a casing using one natural material, it was noticed that there were variations and patterns in the filling pattern, and it appeared that it spread uniformly. This difference in density affects the degree of curl, so pepperoni with casing of collagen material leads to the conclusion that cupping will occur more strongly.


So then is the difference in density caused by this hydrodynamics really affecting curl? In order to verify this, Mr. Kenzi carried out experiments in which four pepperoni sides sliced ​​from the same peperoni were placed on a paper towel and heated with a microwave oven. In the paper towel, the symbols "◯" and "×" are written, and by heating the pepperoni face up, ◯ to face downwards, it is confirmed whether directionality exists in the contraction of pepperoni .


As a result, it turned out that the directions of the cups were superbly matched with ○ and ×. Apparently, it has become clear that one of the reasons for pepperoni to curl is in the internal density difference that remains at filling.


◆ consequences derived from hypothesis 3: drying process and density
In the case of food processed like peperoni, it is said that there is a factor to be considered, the existence of "drying process".

When drying foods, drying generally progresses from the outside to the inside of the product, so the closer it is to the outside, the higher the dryness and the difference in density. After that, the product is packed in a pack of constant humidity and shipped, it is kept until opening. By putting in this state, the difference in dryness will be homogenized again, and accordingly the density will return to uniformity.

However, the final condition is said to be different before drying and after drying. Even if moisture returns to food once dried, it is not in the same state as before drying, and the changes that occurred in the material itself are not restored. Consequently Kenji's conclusion is that, as a result, inside and outside of peperoni there is a difference in the water holding capacity to keep moisture, the difference will appear as a difference in curling during heating.

The conclusion
Based on the above verification, Kenji concludes that Pepperoni's cepage is caused by the following factors.

·How to pack filling: Difference in density depending on material of casing

·Temperature difference on both sides generated during heating: When heating in a pizza kiln, the outer side which directly touches heat is contracted and the side where heat is diffused in pizza dough does not shrink

·Difference in water holding capacity occurring inside and outside of Peperoni: Degree of cupping is affected also by changes occurring during processing

In this way, taking a curl of peperoni, it was that when I tried it hotly, I found various things. Mr. Kenzi's friend, who studies material science at Cambridge University, said he created a computer-simulated video of the difference in shrinkage caused by the difference in heat added to Peperoni.

Pepperoni Curling Demonstration - YouTube