The Thermodynamics of Cooking

Mise en Place: Where Meat Meets Heat

As a chef, people often ask me for cooking tips/tricks, or shortcuts to make their time in the kitchen easier. It's a tough question to answer- it's like asking a concert pianist how to skip all of the hours of practice and get right to mastering the piano¹. The point is that over the last few years I've spent ten plus hours a day honing and refining my ability to prepare and cook food, so how am I supposed to answer this question with a simple trick that allows them to gloss over the many hours of hard work (and many mistakes), making anything they do in the kitchen super easy and fail-safe? It's just not that simple, I'm sorry- but isn't the journey worth as much as the result?²

My aim is not to scare you away from attempting anything in the kitchen; quite the opposite, actually. If you have the proper perspective and preparation going into a project, the outcome will be more favorable. What I want to share through a series of posts, before I begin with recipes, is a few principles on how to properly prepare yourself in the kitchen.

Most chefs enter the kitchen as a prep cook³ and for very good reason. As a prep cook⁴, you learn first to take orders from those above you in rank⁵ and knowledge (not always the case). Second, you learn all of the menial tasks that can drive a person mad⁶, yet are imperative to achieving high quality in the final product. The beauty of this setup is that the prep cook is able to aid each more experienced chefs⁷, learning each of their duties, and learning from their experiences. A chef de partie, for example, has graduated into this role, as it is more specialized, so there are fewer opportunities to learn the process of the entire kitchen. So as a prep cook it's a great opportunity to see the various roles in the kitchen, and learn the techniques necessary to prepare the mise en place⁸ for the other chefs.

And that's the key phrase for this piece: mise en place. In the kitchen you want to be as prepared as possible before flame hits the food. The old military adage ‘proper planning and preparation prevents piss poor performance' is often repeated in kitchens⁹, and for good reason. So, again, before I get into recipes, and recipe videos I want to explain how a working understanding of the cooking process, a properly equipped kitchen, and basic knowledge of timing in the kitchen can be the best utilities to enhance your kitchen endeavors. Today we'll look at the process of cooking itself.

The act of cooking is such a broad term now; it traditionally is used to refer to applying heat to food in order to produce a different flavor and texture, but something like sashimi has no application of heat - yet with all of the detailed cuts and alterations of ingredients, I would still describe the process of preparing it as cooking. In any regard, cooking is the process of changing a raw ingredient into something more flavorful and complex. For now, let's focus on cooking with heat- specifically, what's happening when you grill.

First, let us understand that when it comes to food, not all food is constructed in the same way. The composition of a zucchini is far different than the composition of a filet mignon, so we can't cook it in exactly the same way. We can absolutely grill the two of them, but we must do so in different manners.

Vegetables are mainly composed of water, usually north of 70%, and contain very little fat and protein¹⁰, while our filet mignon can contain as low as 50% water and up to 30% fat and protein. In either case, both are composed mostly from water but the vast difference in protein composition explains why we cannot cook them the same way and expect the same results.

Imagine the best steak you've ever had¹¹- the “crust” is where most of the flavor comes from. So if the crust is the most flavorful, it stands to reason that with a solid understanding of how to achieve it we can greatly improve the flavor in our cooking. The reason a crust is created is due to the Maillard Reaction¹²which describes the process in which the breakdown of proteins and sugars present result to form new and complex flavors, as well as ridding those protein cells of water. While water is indescribably important to our existence, it's notoriously unflavorful¹³.

So, if the crust is the most flavorful part- why don't we just cook a steak so it's all crust, i.e. browned? At that point, we're not talking steak, we're talking beef jerky¹⁴. So the real key then becomes finding the desired balance between seared outside, and juicy inside; this is most easily accomplished by triggering Maillard Reaction quickly, to create the desired crust, without denaturing too many protein cells¹⁵ within the steak, leaving it moist and tender.

This is achieved in two steps: 1) using a heat supply with enough energy output to trigger the Reaction, creating crust; and 2) bringing the internal temperature of the rest of the steak to a point where it too, is at its most tender and juicy¹⁶. This is often when you'll hear BBQ enthusiasts rave about how much BTU¹⁷their gas grill is capable of putting out. In our case, BTUs are great - we want them; but we also have to consider how they're transferring that energy into our steak.

A gas grill operates very simply: it has a number of burners in the bottom of a firebox, which ignite and send high heat upwards towards your grills grates - the amount of energy they put out is measured in those same BTU. With that in mind, when you throw a raw steak onto a hot grill it's going to have heat transferred to it in three possible ways: conduction, convection, and radiation¹⁸. What we really want is to cook our hypothetical steak in (2) stages, using a combination of the (3) different processes. First, we want to cook it over direct heat¹⁹ using a combination of conduction and radiant heat; and then we want to cook it over indirect heat²⁰ using convection.

1. Sear the Outsides, or How to Achieve the Sexy Grill Marks

The grill grates are made of metal (almost always) and thus are a conductor of the heat source generated by your grill's burners. Like our zucchini and filet, not all conductors are created equal- different materials conduct and retain heat differently; for example, cast iron (a poor conductor) heats up slowly, but due to its large mass it retains heat exceptionally well. On the other hand, aluminum is a terrific conductor, it heats up quickly; but because it's a lightweight material, it retains heat very poorly. So if your grill's grates are aluminum, they'll heat up very quickly; but when you throw a raw steak on them, the steak will act as a thermal sponge and quickly sap all of the heat out of the aluminum - ultimately it's going to slow down and interfere with our Maillard Reaction.

Meanwhile, that cast iron, after you let it get hot, will retain much of that heat; so when that steak is thrown on, the heat is going to continuously transfer into your steak at a high rate. Deep, dark grill marks will be produced efficiently, making it the best choice to achieve the Maillard Reaction quickly.  The dark grill marks are an example of the Maillard Reaction that has taken place.

However, cast iron is not found frequently on outdoor grills, and for good reason- cast iron also tends to rust very quickly. So most of the grill manufacturers turn to stainless steel as a solution; stainless steel is a good conductor with decent heat retention, not as good as cast iron, but it will not rust as easily²¹, making it a good choice for outdoor cooking. So these stainless steel grates achieve the conduction we want, but there's another process of heat going on: radiant heat. Radiant heat comes from the burners, or the grease pans beneath your grill grates; radiant becomes more of a factor in charcoal grilling, some unique gas grills²², or infrared grilling²³. Now that we're able to achieve the quick browning we want, we're able to sear both sides of the steak, at 45° and then 135° for the cross-hatch grill marks, quickly, without cooking too much of the inside. This stage is accomplished entirely without a lid; a lid introduces the next stage of heat transfer.

2. Raise the Internal Temperature, Finish the Process

Now that our hypothetical steak has been seared on both sides, it's time for stage two: bringing the inside of the steak to the temperature most desirable to eat. Before we discuss its doneness, let's discuss our convection heating. Most often when we think of convection, we think of our oven. All ovens are, technically speaking, convection ovens. When you're told that your oven is a “conventional” oven, what that means is that in addition to the convectional heat provided by your oven's heating element, your oven also heavily relies on the radiant heat produced by the heating element and walls. A “convection” oven as its termed²⁴, has a fan assisting the circulation of hot air within the oven, therefore increasing the rate at which convective heat can transfer into your food.

Most grills are void of fans (they're not ovens, after all) so with the lid closed they operate more like a conventional oven. In order to most appropriately bring the internal temperature of your steak to the level you'd like²⁵ we must apply indirect convectional heat to our steak, so as to avoid burning²⁶ the outside as we heat the inside. In order to accomplish this on a traditional gas grill, you must have at least (2) separate burner units. The first one (likely the one we just seared our hypothetical steak on) we will leave burning, while the other unit will be off completely. Upon completion of the sear, transfer the steak to the grates above the burner unit that is not on, close the lid, and allow your grill to transform into a convection oven. Because we completed stage one with the lid open your grill will initially be a cold oven that has to preheat²⁷ in order to raise the internal temperature of your steak. Within a short time, your grill has converted into an oven, and is bringing up the temperature of your steak as the hot air within the oven circulates, interacting with your steak. After achieving the desired temperature²⁸ you may pull the steak off of the grill, transfer it to a cooling rackand let it rest²⁹ before contemplating carnivorous consumption.

With that concludes the basic concepts needed to understand what's taking place when you place food on the grill. The lengthy construction and effusive footnotes³⁰ in this post aren't going to be regulars in recipe posts; this is intended more as a document that you can refer back to in the future. The concepts of heat described in this post are related to grilling, but you can think of them as you apply heat in other methods of cooking like sautéing or roasting.

Notes:

1. Malcom Gladwell referred to this as the 10,000 hours rule, arguing it would take roughly 10,000 hours of dedication to any field in order to find success within it.
2. Odysseus, Don Quixote, Luke Skywalker- all heroes whose journey is more important than the resolution.
3. In most restaurant kitchens, washing dishes is the entry level position. Many kitchen managers view washing dishes as an onsite interview. Sure, anyone can wash dishes- it's a menial task; that is until you're doing it every day, 10 hours a day with minimal compensation and continual sogginess- many aspiring monks would be well served first learning patience in the dish-pit.
4. The prep cook is one of the few positions in the kitchen without a special French name; there's a name for nearly every other possible position in the kitchen, e.g. Sous Chef, Garde Manger, etc.
5. The French “Brigade” kitchen so closely resembles an army, and it's no coincidence. Developed by Georges Auguste Escoffier, the Brigade system is designed to provide a hierarchy for chefs in large kitchens so that responsibilities and delegation is as clarified as their butter.
6. Cleaning mushrooms one by one with a mushroom brush, for example.
7. Also known as station chef, line cook.
8. Literally “put(ting) in place.” This phrase has grown to mythical status in kitchens, its utterance is like a priest referring to Him. It's important, and in the kitchen everyone knows why.
9. Also referenced in Anthony Bourdain's Kitchen Confidential: Adventures in the Culinary Underbelly.
10. That's why your parents always told you to eat your vegetables.
11. If you're a vegetarian and have never eaten a steak, I apologize. I respect your choice, and vegetables are delightful, but steak is delicious nonetheless.
12. The Maillard Reaction is named for the French chemist Louis-Camille Maillard who happened upon it when he was trying to figure out how amino acids linked up to form proteins. The reaction occurs most readily between 300° F to 500° F when proteins begin to denature and recombine with the available sugars^a.
    1. Often confused with Caramelization, which is the process that describes the non-enzymatic browning reaction, involving the removal of water with the breakdown of the present sugar.
13. Think beef jerky. Dehydrated beef that's had nearly all of its water content removed, leaving only flavor.
14. See note 13.
15. I.E. drying the meat out.
16. New science (well, with the last 30 years) has brought us a new way to achieve the perfect steak temperature with the immersion circulator- also known as Sous Vide; cooking with Sous Vide is brilliant, and I will delve much, much more into Sous Vide cooking in the future^a.
    1. In a nutshell, Sous Vide cooking is achieved by vacuum sealing your food in plastic and then submerging it in a heat controlled water bath that cooks it to a very specific temperature, gently. It's beautiful.
17. British Thermal Unit. A traditional unit of energy equivalent to about 1055 joules. It is the amount of energy required to cool or heat one pound of water by one degree Fahrenheit.
18. The three types of heat transfer used here:
    1. Conduction refers to the process of heat transfer through direct contact of a heat source
    2. Convection refers to the process of heat transfer through a fluid, such as air, water, or oil. Baking in your oven is cooking by convection.
    3. Radiation refers to the transfer of heat by direct exposure to a source of light energy- when you put a marshmallow on a stick and roast it over an open fire, you are cooking it via radiation.
19. Direct exposure to a heat source, e.g. cooking over coals.
20. Indirect exposure to a heat source, e.g. cooking in an oven.
21. Grill manufacturers are allowed to use various types of stainless steel and still call it stainless steel. Typically, the highest quality available is #304, or 18/8, referring to its composition of 18% Chromium and 8% Nickel. **Look for 304 stainless steel when buying a grill.
22. For example, DCS grills feature ceramic briquette trays to mimic the radiant heat from charcoal, but within a gas grill. These are great grills.
23. Increasingly popular now, Infrared grilling refers to the radiant infrared waves emitted by the configuration of a special burner. Typically, a gas or electric burner heats a solid surface, most often ceramic, which then radiates far infrared waves directly into the food. This type of heat transfer is supremely efficient, and reaches very high temperatures that a standard gas grill cannot^a.
24. As if things weren't confusing enough.
25. Temperatures of doneness traditionally range from
    • Rare (cool red center, 120°F-126°F)
    • Medium Rare (warm red center, 126°F-134°F)
    • Medium (warm pink center, 134°F-150°F)
    • Medium Well (done throughout, slight pink center, 150°F-160°F)
    • Well Done (tough brown center, 160°F-Don't Bother°F)
26. Seared outside-good; charred outside-bad.
27. Just like a cold oven that needs to be preheated, an open grill has allowed all of its convective and radiant heat to escape the air surrounding your grill. So when you close your lid, it will take a period of time^a for the grill to fully replicate a convection oven.
    1. By now you've noticed I haven't given any specifics on time for these stages and events. That's for two reasons; one, this post is intended more to help you understand the theoretical process of what's taking place when you grill. And two, there are far too many variables¹ for  this already long post.
       1. Such as grill size, BTU capability, the grill's material, the cut of steak, its thickness, your desired doneness, and even the weather you're grilling in. Believe me, I will get more into specific detail in recipes and the recipe videos.
28. In the future, I'll do a video demonstrating all I've discussed here, on grilling the perfect steak. In that video you'll see me touching and prodding the steak frequently, not because I like to touch meat, but to determine its doneness. A good rule of thumb^a when checking for doneness is to take your thumb and index finger and press them together lightly^b, now touch the fatty part of your palm between your index knuckle and the base of your thumb. It should feel flabby, much like a rare steak. Repeat this process with the proceeding digits and think of the increasing levels of doneness, i.e. middle finger-medium rare, etc. This is a decent representation, but it's not fail safe- ultimately it takes practice, and understanding different cuts of steak. A medium rare filet mignon is going to fell much different than a medium rare ribeye.
    • a. Pun intended.
    • b. See figure 1.
29. On the edges of your steak, the cell walls have been severely damaged by the Maillard Reaction, tightening the muscle fibers like wringing a sponge, sending the water within those cells outward- both outside the steak (which is the sizzle of a steak, it's water quickly evaporating on the surface) and inside the steak. This is why the center of a steak pools the juices. Resting your steak allows these juices to redistribute throughout the steak. Rest your meat, please.
30. Maybe some footnotes, because I love footnotes.