Grilling is one of the most popular ways to cook food. Even our earliest ancestors cooked over an open flame. Today, we use more advanced methods, like infrared grilling, to achieve the same result.
Though grilling evolved over the centuries, firing up a grill to prep your favorite meal remains an easy and enjoyable way to cook. But, how does it work?
Why Do We Cook Food?
The short answer is that cooked food is safer and tastier. However, that’s an oversimplified answer.
There’s no doubt that humans can’t ingest the raw version of some foods (like meat and eggs) because they contain bacteria that poisons us. Cooking these foods kills harmful bacteria, so we don’t get sick. But, that’s not all.
Cooked food is easier to chew, break down, and digest. Raw foods can be tough to chew, which affects the body’s ability to digest it. By cooking foods, we alter many properties in the food, including a breakdown of some components for easier digestion.
Naturally, we can’t overlook the taste factor. Though it’s purely psychological, it matters. Cooked food is more palatable, so humans eat things they wouldn’t normally enjoy in raw form.
How Do We Cook Food?
Cooking food makes sense, and there’s more than one way to make it safe and delicious. From improving flavor and texture to simplifying the entire process, we developed hundreds of ways to cook food.
- Fried food, like French fries, result from dropping potatoes into heated fats or oils. The process cooks quickly and infuses it with extra flavor.
- Baking makes some of the tastiest foods known to man. Cakes, cookies, breads, and pastries exist because dry heat (usually from an oven) and liquid in the mixture make steam, which cooks the food.
- Pasta-lovers know all about boiling food. Bring a liquid (usually water) to its boiling point and add the food to cook it thoroughly.
- Simmering is similar to boiling. Food cooks in a liquid that maintains a temperature below the boiling point. It takes longer but works wonders with veggies, sauces, and soups.
- Steaming involves immersing food in the water. Heat the dish until the water evaporates to create steam to cook the food.
- Roasting is similar to baking because it uses dry heat, but it can be done in an oven or over an open flame. Food is placed in a specific type of pan or on a spit to heat it evenly.
- Grilling (our favorite food prep method) applies dry heat directly to the food.
Clearly, humans put a lot of effort into developing cooking methods. As our understanding of chemistry and physics changed, so did our approach to cooking.
Wait, this article was supposed to be about cooking food. Why are we talking about science?
As it turns out, cooking, especially grilling, uses scientific principles to achieve results. Cooking is a transference of energy that alters the food on a fundamental level. Did you ever think that learning the science behind grilling just might improve your next backyard BBQ?
Cooking Outdoors: The Science of Grilling
What does every cooking method have in common? If you answered heat, you’re not wrong, but you’re not completely right, either. Cooking actually relies on energy, though heat is commonly involved in most methods.
Heat vs. Temperature and Why It Matters
All three grilling methods we discussed use heat to cook your food. However, they deliver heat in different ways and consequently cook food at different speeds.
It’s important to understand the difference between heat and temperature before we continue. While heat and temperature are related, they represent very different things in terms of grilling.
- Temperature is the amount of energy in individual atoms.
- Heat is the total energy of all atoms together.
Think about it this way. Heat your oven to 200°F. You could put your hand in the oven and wave it around to feel the heat, but it wouldn’t harm you. However, touch one of the metal racks in that 200°F oven, and you would suffer burns.
Both the air in the oven and the racks are 200°F, but only one sent you to the emergency room. Of course, if you held your hand in the oven for a while, the hot air could eventually damage your skin.
Three Methods of Heat Transference in Outdoor Cooking
When it comes to grilling, there are three different methods to choose from. They all involve energy transference, and they all yield slightly different results.
Conduction
Transferring energy to the food by direct contact is known as conduction. Think about the scorch marks on a hotdog, burger, or chicken breast. Those are both cases of conduction where the hot metal grate transferred energy to the meat.
Convection
When air, water, or oil carries energy to food, it’s known as convection. While the hot grate delivers scorch marks to your hot dog, burger, or chicken breast, it isn’t the only thing cooking your meat.
The air moving around the other sides of your meal is just as active in the cooking process. In fact, gas grills rely mostly on convection to cook your food, even if they leave those appealing scorch marks on your meat.
Radiation
Cooking with radiation means using a light source, like infrared energy, to transfer heat directly to food. Charcoal grills, campfires, and infrared grills rely on radiation to cook food and give you a deep brown sear on those hotdogs, burgers, and chicken breasts.
To be fair, there are a few other ways to cook, but these are the three methods most commonly used for outdoor grilling.
How Heat Transference Cooks Food
Convection, conduction, and radiation walked into a backyard BBQ and… just kidding.
Different types of grills use different methods of energy transference to cook your food. That means grills cook at different speeds even if they reach the same temperature.
As demonstrated in the 200°F oven, you can see that convection cooking is slower than conduction. You would have to hold your hand in that oven (convection) for a while to see the same results as a quick touch to the metal rack (conduction).
Why does that happen?
The metal of the rack is a lot denser than the air in the oven. That means the rack delivers more energy than the air in the oven, even though there is no temperature difference.
Also, energy dissipates as it moves away from the source. The metal rack holds the energy in its bars. Air is less concentrated and moves around the oven.
How Heat Affects Your Food
Hopefully, you now have a basic understanding of energy transference, heat, and temperature. Many grills rely on more than one form of energy transference to cook food, but the majority of cooking is done by the food itself.
What? Are you picturing a thick, juicy steak grilling itself? That’s not exactly right, but it’s amusing to imagine.
The truth is, whatever method you use for grilling your meat, it’s just the beginning of a chain reaction that results in a meal.
When you grill, you excite molecules in the air around your meat and encourage them to transfer heat. Those molecules excite the molecules in the meat by transferring the heat. Molecules on the outside of your meat transfer heat inward to excite more molecules and spread the heat.
This explanation is fairly simplistic, but it works for our purposes. The transfer of heat creates a wave of energy that spreads throughout the entire piece of meat. So, in a sense, the meat cooks itself once the hot air around it triggers the chain reaction.
How Do You Know Your Food is Done?
It’s important to note that your food doesn’t stop cooking just because you remove it from the heat source. We know this as the carryover effect. So, how do you know when your food is done?
Remember, you started a chain reaction by putting your meat on the grill. Those molecules want to find equilibrium and remain excited until they do.
To compensate for the carryover effect, remove your meat (especially thicker cuts) about 5°F below your target temperature.
A Note About Cooking Temperatures
We talked about the difference between heat and temperature. When it comes to the temperature of many foods, especially meat, it’s important to know where you stand.
A meat thermometer is an affordable tool for grillers that can let you know if you’re on track, and your food is safe for consumption. If you’re unsure where your meat needs to be, check out this chart for safe minimum temperatures.
What Type of Grill Should You Use?
Phew! That was a lot of science to digest. Now that we have a better understanding of the science behind grilling, let’s take a look at what it means for different types of grills.
How Charcoal Grills Work
Close your eyes and imagine your first backyard BBQ. What do you smell? For many people, the smell of meat cooking over a charcoal grill is a fond memory because of the unique smell. Charcoal grills remain a common choice for backyard BBQs for a good reason.
Charcoal grills (and wood fires) can use all three methods of energy transference. It depends on the design of your grill.
The charcoal (or wood) produces radiant heat in the bottom of your grill. Grill grates absorb the radiant heat from the charcoal and conduct it into your food. Hello, scorch marks!
However, if your grill also has a lid, you can also create convection heat. When you put the lid on, you hold the radiant heat in, so it circulates around your food.
Even with the lid off, heat still circulates around your food, but most of it dissipates into the air. The top of your food doesn’t heat up as much as the bottom, which can lead to uneven cooking. Plus, it tends to take a lot longer than when you use the lid.
Cooking with a Gas Grill
Gas grills are a cleaner, popular alternative to charcoal grills. You don’t have to worry about disposing of embers, ashes, or used briquettes.
However, you do need a steady supply of gas, usually natural gas or propane, to power your heating element. Gas grills use protector bars, lava rocks, or ceramic briquettes as radiant heating sources instead of charcoal or wood.
Other than the difference in the heating source, gas grills function much like charcoal grills in terms of cooking your food. Choosing between charcoal and gas grills comes down to personal preference.
What About Infrared Grilling?
Infrared grilling, also known as radiant grilling, works a little different from charcoal and gas grills. It’s a newer grilling method that warrants a more in-depth discussion.
How Infrared Grilling Works
A special plate absorbs radiant heat from burners and emits it in a different form. Grates absorb the heat to cook the bottom of your meat by conduction.
Heat also bounces off the specially designed grill interior to focus convection heat onto your food. While infrared grills use some convection to cook food, less air moves around, so the energy is more concentrated than charcoal or gas grills.
Benefits of Infrared Grilling
For many people, infrared grilling means more flavor, more energy, and a superior culinary experience. Radiant grilling focuses on heating the meat instead of just warming the air around the meat (though it does some of that too).
- Infrared grills preheat in five minutes or less.
- Expect a more even heating surface due to the design and structural elements.
- Meat retains more natural juices because radiant grilling doesn’t dry the air out to heat it up.
- Infrared grills are energy efficient and easy to clean in comparison to gas and charcoal grills.
- You still get those beloved scorch marks.
Types of Infrared Grills
Currently, there are three types of infrared grills to choose from. Before jumping into radiant grilling, you want to make sure you choose the right infrared grill to meet your needs.
Ceramic infrared burner systems are the most common. They use stainless steel burners with a ceramic surface that produces small, but extremely hot flames. Ceramic infrared burner systems are best for people looking for that hot, fast sear you can’t achieve at lower temps.
TEC, the founder of infrared grilling, created a radiant glass panel system that delivers the almost unbelievably even heat distribution. You can adjust the temperatures to handle vegetables without melting them and crank it up hot enough to land those scorch marks you love.
Heat emitter systems give you reasonable heat distribution, few flare-ups, and a decent temperature range. However, they don’t quite hit the levels you need to get that steakhouse sear.
What About Smokers?
Were you wondering if we’d mention smokers in our outdoor cooking discussion? How could we not? Smokers live in a world of their own when it comes to backyard BBQ.
When you commit to using a smoker, you invest time in cooking your meat. Incidentally, smoking meat used to refer to a method of preserving it, but today it means delicious BBQ.
While infrared grilling is all about speed, smokers take the long road. Cooking meat in a smoker can take twelve hours or more. But, oh, that finished product. From pulled pork to a rack of ribs, smokers imbue flavor, retain juices, and create a dark, chewy crust (known as bark) around your meat.
Is your mouth watering yet?
How Do Smokers Cook Meat?
Smokers use wood to create indirect heat that circulates around your meat. Unlike the other types of grilling, smokers skip conduction and focus on convection heat transference. Good smokers keep the heat moving around the meat to cook it evenly.
Using Your Charcoal Grill as a Smoker
If you already have a charcoal grill, you can easily convert it into a smoker. Surprised? So were we, but it’s true. Are you ready to have your mind blown?
Charcoal grills already use charcoal briquettes to create indirect heat. All you have to do is cut off the direct heat.
To cut off the direct heat, slide all of your charcoal to one side of the base. Leave the other side completely empty. Ignite the charcoal and let the briquettes burn like normal.
You can absolutely use the charcoal side to sear your meat, but the other side now works as a smoker. Put your meat on the non-charcoal side, replace the lid, and let it cook.
It takes a little work, and you may want to monitor the temperature with a meat thermometer, but it’s doable. Just make sure you keep the charcoal burning and work that temp somewhere between 225°F and 275°F for best results.
Grilling and Your Next Backyard BBQ
Will you ever look at grilling the same way again? Knowing the science behind how grilling works may help you choose the best grill and prepare a better meal, but it all starts with quality ingredients and a love of food.