Fire — nature's microwave. It has been a source of warmth, light, and ways to scare off Frankenstein's monsters since time immemorial. Humanity wouldn't be where it is without it, which, given how the world is literally on fire right now, might've not been the best move.

But there is perhaps no greater contribution to fire than making our food delicious. Be it by heating a pot of water or by charring some veggies to turning steaks from red weird things to brown goodness. Fire is synonymous with cooking. Everything fire touches becomes instantly, 100% better.

Which is why people don't know how to use it.

You see, people think that more fire + more deliciousness, which is how you end you with a burnt cake.

There is a reason why stoves don't come in only a switch between Off and Hotter Than The Sun In A Bikini. Temperature and time go hand in hand, which is difficult to do when you're nuking your food with everything you have. Foods have different thicknesses and compositions which require different types of cooking at different temperatures.

For a rare steak, you want less time and high temperature to make that brown crust appear, while something like a stew requires low temperature and more time to make the flavors integrate like an after-work mixer.

Since we have to make our ingredients last, as cow's stomachs are now well suited for radioactive grass and steaks are hard to come by, before trying to make anything, we first have to learn about how to make food, how to cook, and how heat works. Basically, today we will learn the basic principles of cooking so you don't go burning down the house.

1. Why do we even cook?

Cooking food has two basic objectives:  to make food more bearable to our feeble human tummies, and to provide flavor and aroma. On many occasions cooks when cooking food achieve both goals at once, as heat breaks down molecules responsible for toughness, and in turn, chemical reactions are triggered that form aromatic compounds. The smell-good molecules.

Heat increases the mobility of atoms and molecules, and as such, increases their energy, making them transform and react. Basically, we transform food. Did you know that alchemy was born in the kitchen? In that way, we are all apocalyptic alchemists. Add that to your list of titles. Lord/Lady [INSERT YOUR NAME HERE], Spice Emperor, Apocalyptic Alchemist.

The molecules collide with each other, they deform, and when like-minded groups meet, new interactions occur between them giving rise to new compounds. Kinda like a molecule fanclub creating new O.Cs.

Another object of cooking is the elimination of microorganisms, which we already talked about.

2. How do I harness the ancient power of fire to strike fear in the heart of my enemies? And also to cook my food, I guess.

Cooking can be broadly defined as converting raw food into something different(See Apocalyptic Alchemy). Very often, we transform food by heating them, transferring energy from a heat source to food, to their molecules to make them move faster, colliding each time harder and stronger, and reacting to form new structures and flavors. The different cooking methods, boiling, roasting, baking, frying, etc, achieve their various effects using very different materials as the medium through which heat moves and resorting to different forms of heat transfer.

There are three ways to transfer heat and your knowledge will help us understand how each particular cooking technique affects food.

Conduction:

Conduction occurs when we heat a conductor — like a skillet — and heat is transmitted to through it. The conductivity of a material determines their behavior on the stove. The better the conductor, the faster it will heat up and cool down, and the more evenly it will distribute the heat through the bottom of the container.

Irregular heating creates spots that can burn food. Inside the food, the heat goes from the outside to the center of the piece (meat, fish, vegetables). Due to the cellular structure of food that prevents the easy movement of thermal energy it's better to use low heat over a longer period of time to penetrate it. One of the keys to good cooking is knowing how to heat food until properly done in the center without overheating the outer parts.

Convection:

A convection current occurs when a liquid absorbs heat in one place (the lower part, which is in contact with the fire). This produces a decrease of density, so it moves upwards and the cold liquid with greater density drops. This is what happens when we heat a liquid in a pan. This phenomenon also occurs in convection-steam ovens, in this in the case of humid air or steam, when heated they rise and when they cool they descend, thus producing the currents of convection. Thus, ovens are hotter on the upper part and colder on the lower parts. Heat goes up!

Radiation:

Radiation is the emission of energy from the surface of all bodies. Its energy is called radiant energy and is transmitted in the form of waves, which are invisible, like airs, or ghosts.

When a body is at 800ºC/1472°F or more, they emit enough visible radiant energy to be self-luminous and is said to be red hot. When they strike a body that is not transparent to waves, for example meat, they are absorbed, transmitting heat to the body, and therefore cooking it.

The microwave also heats by radiation, as the waves penetrate the food, in the same way that light passes through crystals. Upon reaching the center, the water contained in the molecules is heated and this heat is transmitted by conduction up the surface, heating and cooking.

As an interesting side note, when an atomic bomb is detonated, there is a very small strip of distance where the radiation is strong enough to cook all the food contained in it. Sadly, it would also cook you, and humans are way too gamy to be delicious. Maybe with some rosemary. Also, they will be charred. We don't like charred.

After looking at the three mechanisms of heat transmission, conduction, convection, and radiation, it is time to analyze the main techniques of cooking, in which the means of cooking will be dry or humid air (steam), water, or fat.

- When using dry air without heating fluid, the infrared rays of the radiation cooks roasts on the grill, to the spit, in barbecues, and gratins.

-When using humid air, as a medium or heating fluid, convection guarantees the perfect cooking in roasts, in the oven, in salt, papillote, etc.

-When using a liquid, such as water as a heating medium or fluid, convection will result in a boiling.

- When using steam, as a medium or heating fluid, convection will result in a steam cooking.

When using a fatty body like oil, as a heating medium or fluid, conduction will result in frying.

There are other cooking techniques in which the means and mechanisms of heat transmission are several at a time, for example braising; first to browning the food, conduction will be present and when adding the liquids the convection will act in a liquid giving rise to a boil, which in turn when the container is hermetically sealed will provide steam which will lead to convection. Regardless of the technique used or the appropriate heating fluid, in the food that we are cooking, there will always be conduction to transmit the heat from the outer molecules to their core.

3. Brown is the tastiest color.

As I have already mentioned ad nauseam, chemical reactions happen when cooking, depending on the technique we use. Cooks are nothing but glorified scientists using their science magic to make things better. But since people look at you weird when you say that you have mastered the power of fire and the color brown.  Thus, we must understand a few basic stuff.

Maillard's reaction:

It was described by the French scientist Louis-Camille Maillard in 1916, which explained that a complex chemical reaction that occurs between proteins, sugars and fats when heated. By reacting during cooking, they transform and interact with each other in a complex way, giving rise to browns pigments, aromas and flavors. This reaction occurs in four different phases:

1st Phase. In this phase the union between sugars and amino acids (proteins) starts. There is no change in color.

2nd Phase. In this phase the sugars dehydrate and the colors turn yellowish. The production of odors begins.

3rd Phase. Also known as the yummy-yum-yum phase. In the third phase, dark pigments begin to form (melanoidins), because the compounds in earlier phases polymerize (come together to form a larger molecule).

4th Phase. The last phase is known as the Strecker degradation. In it they form aldehydes that are low molecular weight compounds that are easily recognizable by their burnt smell. Basically, this is where things go too far and they burn. The sugars and protein decompose and die.

The principle of osmosis:

Osmosis is the exchange of water between two bodies with different solute concentration through a semipermeable membrane until they equal their composition. Think of it like a sponge that you put on a tub of water. Its gonna absorb water until it can't hold it anymore.

In the event that the membrane is more permeable, not just salt will exchange, but many more components. Imagine a soapy sponge that releases the soap when entering the tub.

This is what happens when we cook meat in water or a concentrated broth. Being meat more concentrated, the meat juices will go into the broth. If the liquid is hot, the transfer of juices will be less since the meat will close its pores, hence why soups and stews take longer. After all this, if what we want is to enhance the flavor of a broth, we will put foods cold, with water, to extract from them the maximum amount of substances.

The process of protein denaturation:

Denaturation is the structural change that proteins undergo from their native form after they have undergone a series of agents. These can be heat, a change in pH, etc. During the cooking process, some of the proteins food contain alter their state. For this same reason an egg goes from a liquid to a solid state when fried.

And what a note to leave this chapter in, because next chapter, we will see how all this is applied when we use Eggs to test your knowledge! There are a lot of cooking methods that can exist, from papillote to sous vide, to even and Earth oven, but listing everything won't do any good. It's time to learn by practice.

Kinda how you had to learn how to shoot to fend off the radioactive turtles. Let's hit the ground running!