You’ve been cooking outdoor for a while. And you’ve probably heard of the two zone grilling method before. But maybe you still don’t fully get it.
You’ve come to the right place.
We’re gonna learn more about the method in this article. By the end of it, you’ll get to know a technique that will up your grilling game tremendously. But before I go into the details, let’s briefly go through the relationship between cooking, energy, heat, and temperature first.
I believe this will help you better understand how all these components come into play in this two zone fire setup.
Cooking And Energy Transfer
In layman’s terms, cooking means heating up food until it is consumable. Scientifically speaking, cooking is a process where energy is transmitted through the body of food for a period of time. During that time, all the components of the food are slowly changing their structure which, as a result, makes the food item edible with intended flavor and tenderness.
There are three ways to transfer energy to cook food.
- Convection cooking is energy transferring to food through some sorts of fluid. It can be water, air, or oil. Convection cooking happens when you boil your potatoes or bake them in the oven. Another example would be any type of deep frying.
- Conduction cooking is energy transferring to food through direct exposure to the heat source. Your grill’s cooking grate is a good example. It is the point of contact. When hot, the cooking grate conducts heat to cook the exterior of your food. The end result is the grill marks.
- Radiation cooking is energy transferring to food through the penetration of heat and light waves. There is no direct contact between the energy source and the food. Infrared and microwave are the two primary types of radiation cooking. In a grilling context, radiation cooking happens when you sear your steak with intense infrared energy waves from burning charcoal or gas.
Did You Know? In terms of energy transmission, conduction > radiation > convection. The rate of transfer also depends on the density of the material, the distance between the heat source and the food, and the amount of energy. Meathead from AmazingRibs.com has a great article on this subject.
Energy is critical in cooking or grilling for that matter. It is what creates heat and temperature. Heat is the total energy. The more energy you apply to a material, the hotter it gets. Temperature is a measurement of the average energy. Likewise, the more energy, the higher the temperature.
Also keep in mind that different components in food respond differently to different degrees of heat. That’s why one of the most important things in outdoor cooking is knowing how to control the temperature. Or simply put, the energy transferring between your heat source and the food.
Let’s use meat as an example. It is mostly water. The rest consists of protein, fat, collagen, and sugar. What usually happens inside your grill is that the convection air first cooks the outside of the meat and slowly melts the fat.
Then that exterior becomes increasingly hot and conducts its new energy to gradually break down the protein inside the meat (meat cooks meat, not air). It also softens the collagen and makes some of the water evaporate as well.
All the while, the radiation from glowing charcoal or gas aids the sugar in its chemical reaction with amino acids, creating a brown skin for the meat. Or what we know as the Maillard reaction. Notice that all these things happen at different temperatures as the meat gradually heats up from edge to edge, then from outside in.
Knowing this will give you an overview of how energy (heat and temperature) cook your food. It also helps you develop a strategy or setup that will ensure your food has a tender and juicy interior with a crusty, mouth-watering exterior. All. The. Time.
What Is The Difference Between Direct And Indirect Heat Cooking?
What Is Direct Heat Cooking?
Also known as hot and fast or direct, high heat grilling, it is the oldest form of cooking. Cavemen used to do it with a stick, a fire, and a piece of sabertooth meat. In this day and age, it is what most people refer to when they talk about grilling.
Simply put, high heat grilling is cooking food with the energy source directly underneath it. For a charcoal grill, the heat source is usually a single and even layer of charcoal across the grate. For a gas grill, it’s turning on all the burners.
Burning charcoal and gas produce radiant waves that heats up the cooking grate. As the grate gets hot, it conducts energy to cook the food sitting on top of it. If you close the lid, it will trap the convection air inside and slightly cook the sides and top of the food as well.
However, if you open the lid instead, the radiant heat will just focus on the bottom of the food, browning it as a result. In this case, you also want to flip the food often to avoid burning the bottom surface.
Direct heat grilling with the lid up is good for thin and quick foods that require some basting. Cooking with the lid down tends to overcook these foods. So generally, I’d recommend the first type.
Some examples for quick and thin foods are vegetables, skirt steaks, shrimp, burgers, and fish fillets. Pretty much anything that has a lower fat content and is less than 1” in thickness should go with direct heat grilling. The high heat will cook through the thin meat faster and the lack of fat will not cause any unexpected flare up.
Now, the temperature can get up to 500F with direct grilling. If you cook a brisket with that, good luck, amigo! As I mentioned above, different compounds in food react differently at different temperatures. The high heat from direct grilling delivers too much energy at a rapid rate that some parts of the brisket don’t have enough time to respond. The result is a stiff, blackened outside with a raw, uncooked inside. A disaster indeed!
And because of that, we should always cook any thicker and larger cuts of meat with indirect heat grilling.
What Is Indirect Heat Cooking?
Unlike direct grilling, indirect heat grilling (or low n slow) is cooking food with the heat source away from it along with the lid down. This means the energy is to the side of the food or completely separated as in the case of an offset smoker.
With the fuel source to the side, the heat generated from there radiates into the lid and, as a result, creates convection air throughout the cooking chamber of the grill. That also heats up the cooking grate, producing conduction heat within it.
All of these energies come together and cook the food on the empty side of the grill slowly and evenly, with the convection air as the main player. It’s somewhat very similar to your traditional kitchen oven.
For a charcoal grill, the hot coals are usually pushed to one side. For a gas grill, that means turning on only one burner while leaving the remaining one(s) off.
Indirect heat grilling is used for cooking tough, fatty, and big cuts of meat. Things like brisket, pork butt, or slabs of ribs. You can also cook a whole bird and large roasts with indirect grilling. Foods with sweet, sticky sauces and marinades fall into this category as well.
The temperature with indirect grilling is within the range of 225F to 300F. A bit lower if you live at a higher altitude. And with this temp range, it also means longer cooking time for these types of thick food.
This longer cooking time is actually a blessing in disguise!
You see, all the compounds in meat have a lot of time here. Fat has time to render, protein has time to break down, and connective tissues have time to soften. The heat also has time to work its way to the center of the meat. And because it’s low, the heat accumulation on the meat’s surface is minimal, preventing the heat from burning the surface to a crisp.
And if you use any smoking wood, this also allows the smoke time to stick to the exterior of the meat, imparting that smoky goodness. Not to mention that if you brine your meat beforehand, the heat forces the salt to penetrate faster and bring out the flavor as it heats up the meat.
But this wonderful indirect grilling method does have its drawbacks. The first one is the BBQ stall. It means that the internal temp of the meat just won’t budge after a few hours cooking with low and indirect heat. Fortunately, the solution for this is to wrap it in foil to cook through the stall. This technique is known as the Texas Crutch.
The second drawback is that if you use indirect grilling to cook your ribeye steaks or anything similar, they usually don’t develop a crusty bark like brisket.
These food items are usually thinner (but still thicker than 1”), therefore cooked to their desired internal temp faster. Truth is, they just don’t have the time. Their inside is good to go but their outside is meh.
Introducing the two-zone grilling technique.
What is Two Zone Grilling?
The two zone grilling or two zone fire is a combination between direct and indirect heat cooking. You begin by dividing your grill (gas, charcoal, or wood) into two zones. The first one is a high heat zone where the fuel source is. The second one is a low heat zone where it is empty.
Sounds similar to indirect grilling, doesn’t it? Just hang in there.
Now, you start your food in the high heat zone to char the outside of it. After the food reaches the desired level of beautiful golden brown, you then move it to the low heat zone where the warm convection air slowly cooks the inside.
And of course, you can also reverse the order. Evenly roast the food first in the indirect zone. Once it reaches the internal target temp (use the best thermometer you have), move it to the direct zone so the intense radiant heat can go to work. People call it the reverse sear or the Redneck Sous Vide by John Dawson from PatioDaddioBBQ.com.
Although the two zone fire seems to be similar to indirect heat grilling, they’re somewhat different. With indirect grilling, you slow cook thick food to perfection. But that’s not always the case with food like rib-eye steaks, chicken thighs, or thick pork chops.
Size matters here.
These food items aren’t thick enough that they have enough time to develop a crunchy exterior from constant indirect heat. And if you cook them with direct heat, they’re not thin enough either that it cooks all the way through. That’s why the 2 zone grilling is the answer for this.
It solves the problem that both direct and indirect grilling have by blending the best of both worlds. The 2 zone fire will ensure that your food is juicy and edible inside while crispy and mouth-watering on the outside.
In fact, it’s the most useful grilling technique that you can learn. Master it and you’ll be on your way to grilling Valhalla.
Did You Know? Restaurants everywhere use this two zone direct indirect grilling to cook their steaks. That’s why they always come out perfect every time.
Other Benefits Of Two Zone Grilling
Cooking More Than One Food At Once
Because the two zone grilling creates different heat areas across your grill’s grate, it allows you to cook many types of food all at once. Remember that different compounds in one food reacts in their own way at different temperatures. The same thing is true for different food items.
For example, chicken is safe to consume when its internal temp hits 165F. Yet you can eat your steaks at medium rare doneness, which is around 135F – 140F internal. To get there, you just have to place these two meats at different spots to cook them at different rates.
Likewise, you can put your lamb steak on the low heat zone to bake it first. In the meantime, you start frying your vegetables on the high heat zone. When the lamb steak is ready, throw it on the other side to sear. All the while, move the vegetables to the low heat zone to keep them warm.
Safe Zone For Flare Up Control
The indirect heat zone acts not only as a place to keep food warm but also a safe zone for flare ups. Flare ups happen a lot with direct grilling, especially when fat drips onto the hot coals or burning gas underneath.
By having two heat zones, you can quickly move that fatty piece of meat to the opposite side and wait for the flare ups to subside. Keep in mind that it has no coals on the indirect heat zone. When everything is normal again, you bring the meat back to pick up where you left off.
All in all, the two zone grilling really gives you the full control of your grill, whether to avoid flare ups or decide which food to sear first, as well as the flexibility to batch-cook different types of food en masse.
How Do You Set Up 2 Zone Grilling?
On A Gas Grill
If you have a two-burners gas grill, simply turn on one burner while leaving the other off. If your gas grill has more than two, play around and decide which burner(s) you want to turn on/off. Now, there are a few things you want to keep in mind.
Things like the weather and the amount of meat. If it’s cold and rainy, you might want to turn more burners on. You’re cooking outdoors after all. If you have a lot of meat to cook, crank up the heat to high instead of medium on some of the burners.
Play around and see which setup is best for your cooking needs. As long as you have high heat on one side and low to no heat on the other side, you’re cooking with the two zone fire.
Tip: Remember to have a full gas tank as a back-up.
Now, one exception is the one burner gas grill. You have to put a heat deflector in between the burner and the food. A baking pan is a good choice. You can then put another cooking grate with the food on top of that baking pan. There goes your indirect heat zone.
To cook with direct heat, remove the pan and the food altogether. Then put the food back on to sear. A bit inconvenient but that’s the only way.
On A Charcoal Grill
The charcoal grill is a bit easier to set up than the gas grill. Provided that your charcoal grill has a wide and shallow bottom, you can create a two zone fire with ease. That’s why this technique, along with the Charcoal Snake, is used mostly in a kettle style grill.
The two zone grilling method does kinda work in a charcoal grill with a narrow and deep bottom, such as the ceramic kamado. You just have to buy a half moon heat deflector to create the two heat zones.
However, I find that the grilling real estate is limited on the smaller-sized kamados. Furthermore, the ceramic material is great at retaining heat so it might be difficult to have two distinct heat areas.
Let’s use an Original Weber Kettle as our example. Here is the process on how to set up the two zone fire for a charcoal grill.
- Step 1 – Light your charcoal using a chimney starter.
- Step 2 – When the coals are ready, dump them onto the grill.
- Step 3 – With a charcoal rake or something similar, push the coals onto one side of the grill.
- Step 4 – Put back the cooking grate, close the lid, and let the grill preheat for 10 minutes.
- Step 5 – Start adjusting your vents to get to the right target temp. Don’t forget your thermometer’s probes.
- Step 6 – When the grill is up to temp, begin the cook. Sear or roast first. It’s up to you.
Want a visual demo instead? Here is a video.
Using Water/Drip Pans
Using water pans serve a few purposes in a two zone grilling context.
It adds humidity to the inside of your grill and keeps the meat wet. Combined moisture with combustible gases and smoke particles (if you use smoking wood), it will create a wonderful blend of flavors.
The fire also spends some of its energy heating up the water, which in turn stabilizes the internal temperature of the grill. The water pan collects meat renderings if you place it underneath the meat on the indirect side. Because of that, cleaning up will be much easier and you also have a pan full of tasty juices.
I’d recommend using one of those disposable aluminum pans at any local grocery store. For a charcoal grill, there are two places you can put the water pan. As I mentioned earlier, the first spot is right underneath the meat.
The second spot is on top of the fire. Placing a water pan there will further protect the meat from the radiant high heat. As a result, you cook it more evenly by relying solely on indirect convection air.
On a gas grill, I’d recommend putting your food on the warming rack, if you have one, and the water pan underneath it. Or something similar to the setup for the one burner gasser mentioned above.
That being said, you only need to use water pan(s) for whole birds or large roasts. If you cook steaks or pork chops using the two zone fire, you don’t have to.
Other Variations Of Two Zone Indirect Grilling
These setups are used mostly in a charcoal grill.
Three Zone Fire
Light your charcoal and dump it onto one side of your grill once hot. Make sure that side is about 3 layers of coal deep. From there, slope the hot charcoal pile to 1 to 2 layers deep toward the center of the grill, and finish with no coals on the remaining side.
With this setup, you have a direct, high heat zone on one side, a medium heat zone in the middle, and an indirect, low heat zone on the other side. This setup is similar to the two zone fire but with an added medium heat zone. It gives you even more flexibility and control to cook different kinds of food.
Sear on the high heat zone, then roast on the medium zone. When the food is done, move it to the low heat zone to stay warm. Rinse and repeat on other foods. The only downside of this setup is that you need a charcoal grill with a large enough cooking area.
Three Zone Split Fire
Instead of sloping the hot coals like the three zone fire, you place them equally on either side of your grill and leave the middle empty. With this setup, you will have two direct heat zones and one indirect zone in the middle.
This setup is great for roasting pork loin or chicken rotisserie. That’s because the even radiant heat coming from both sides plus the surrounding convection air.
Ring Of Fire
As the name suggests, your hot coals will be around the inner perimeter of your grill with the center empty. Since the center doesn’t have a lot of room, this setup is excellent for cooking upright or beer can chicken. All the direct heat will surround the chicken, cooking it all around.
Opposite from the Ring Of Fire, the Bull’s Eye has the direct high heat zone right in the center of the grill with nothing around the perimeter. The Bull’s Eye is the preferred setup for cooking and warming small pieces of food like chicken wings. You can also sear meat in the center if you want to.
Malcolm Reed from HowToBBQRight.com uses this setup to cook some delicious chicken wings. Check out his video below.
Note: The cut-off conical steel thing Malcolm has in his video is from Vortex BBQ. Great little tool!
Try It Out
The two-zone fire is the most versatile method you can use to improve your outdoor cooking. It combines the hot n fast grilling and the low n slow barbecuing together. You can use this technique for pretty anything.
It just works.
But remember that size does matter here. The thicker and bigger the meat, the more time it has to spend on the indirect heat zone. The thinner and smaller the meat, the more time it has to spend on the direct, high heat area. Also don’t forget that lid up for hot n fast and lid down for low n slow.
Now, it’s time for you to do it. Try it out and let me know how it goes for you in the comment section down below. Please don’t hesitate to share this to friends and family. They might thank you later.
And with that, have a good one.