Mastering Multi-Zone Grilling
Imagine for a moment that you’ve been tasked with cooking beef tacos in your indoor kitchen using a tri-tip roast (because we’re feeling generous, this hypothetical also involves you eating them). You’d start by pan-searing the tri-tip over high heat, then transferring it to the oven to finish at more moderate temperatures. While the roast cooks throughout, you’d need to caramelize peppers and onions over medium-high heat, and maybe even get a light char on the tortillas in a separate pan. Add it all together, and that’s 3–4 separate temperature zones used at the same time during a single cook, one of the many luxuries of indoor kitchens. Wouldn’t it be nice if your grill could be similarly flexible?
Actually, it can! That’s the magic of multi-zone grilling, today’s Master Grillabilities® topic taught by Weber Grill Master Kelsey Heidkamp. Arranging multiple grill zones is what allows Kelsey to execute the entirety of her grilled tri-tip tacos recipe on the Weber SmokeFire pellet grill; as we noted above, cooking a tri-tip roast indoors requires you to move from the stovetop to the oven (or vice versa, for all you reverse-sear disciples out there). But a grill with multiple heat zones can simultaneously function as both an open-flame stovetop and oven, granting you more flexibility, confidence, consistency, and even safety as an outdoor chef. Any grill type can support multiple temperature zones, making this a universal master skill that requires no extra equipment, though certain accessories help in some cases. Once you’ve mastered multi-zone grilling, you’ll have a whole new outlook on the possibilities every time you light the BBQ.
What Is Multi-Zone Grilling?
Multi-zone grilling is a technique that involves setting up and cooking with multiple temperature zones on the grill. Sure, even Captain Obvious might raise an eyebrow at that explanation, but it’s an incredibly simple concept that yields awesome results. Just think about how often you put multiple burners to work on your indoor range — it makes cooking much more efficient and flexible, right? Multi-zone grilling lends the same benefits (and then some) to home cooks, only without sacrificing the grilled flavors we all know and love.
In its most basic form, the goal of multi-zone grilling is to create 2 distinct heat zones: one with high heat, and another with low heat. We call this dual-zone grilling, which harnesses the power of both direct heat (flames below the food) and indirect heat (no flames below the food) to expand your cooking options across the same grill grate. Thin foods and meat that appreciate a good sear go on the high, direct-heat zone; larger, tougher items belong on the low-temperature side circled by indirect heat. Smart grillers move food between the zones as needed, and may even establish additional zones to cook more food at once or have greater temperature variance. That being said, using multiple grill zones to your advantage requires an understanding how direct and indirect heat behave.
Direct Heat vs. Indirect Heat
This discussion starts with the 3 types of heat transfer: conduction (via contact with a heat source), convection (via moving fluid or air), and radiation (via invisible, electromagnetic waves). Each occurs inside a grill at the same time — hot grates channel conduction heat, hot air within the grill dispenses convection heat, and infrared waves from the fire carry radiant heat. For the purpose of temperature zones, however, we’re primarily concerned with convection and radiant heat transfer.
Direct Heat Is Radiant Heat
Let’s start with radiant heat, the main transfer type of direct zones. By placing food directly above the flames, you’re exposing it to the constant emission of radiant heat waves. Think of it in the same way the sun warms or even burns our skin; we aren’t making contact with the sun (nor would we recommend doing so), but we receive its heat simply by being in the path of its wave emissions. This makes direct-heat grilling the way to go for cooking thinner foods and searing the exterior of meat. When Kelsey cooked the tri-tip roast, she started by searing it for 5 minutes a side in the direct zone. “The 5 minutes over (direct heat) gives it a nice crust,” she says. “It caramelizes the sugars in the rub and binds them to the outside surface of the meat.”
Indirect Heat is Convection Heat
Then there’s convection heat, the product of an indirect-grilling setup. When food is placed above a flame-free section of the grill adjacent to the heat source, hot air circulating within the grill cooks it at a much slower rate than what you get from direct, radiant heat. Furthermore, shutting the hood of a grill with an indirect-heat zone recreates the same conditions as your kitchen’s convection oven. This is ideal for cooking larger and tougher cuts of meat, which is why Kelsey moved her tri-tip roast to the indirect zone after giving it a lovely sear over direct heat. As she says, “Convection heat is really about bringing the internal temperature of the inside of the meat to whatever target temperature you want it to be.”
What about Conduction Heat?
If food’s on a hot grill, then conduction is occurring. The question is to what degree the grates are channeling conduction heat to your food. This goes back to the basics of direct vs. indirect heat — grates directly above the flames will be hotter, and therefore channel more heat, because they’re absorbing radiant heat from the flames; grates adjacent to the heat source won’t be as hot or channel much heat because they’re being bathed in the lower temperatures of convection heat. Conduction heat is what causes bold sear marks on meat as opposed to an all-over crust, but it doesn’t factor too heavily into the broader concept of heat zones.
Benefits of Multi-Zone Grilling
For as much as grilling is thought of as a hot-and-fast game, that approach can get you into all kinds of trouble. We’ll start with the simplest risk: overcooking or outright burning food. Still not convinced? A single, hot temperature zone leaves you vulnerable to potentially dangerous flare-ups, limits your grill to one cooking style, and greatly reduces your margin of error on the grill. The answer to those issues, of course, is multi-zone grilling and its many benefits. Let’s go one by one to illustrate why this technique is in every grill’s master’s toolbox.
Multi-Zone Grilling Gives You Better Temperature Control
Not all food cooks at the same rate, nor does all food contain identical protein structures and chemical compositions. Most of us take this simple fact for granted, but it’s why food reacts to different types of heat in different ways. The key, then, is controlling the heat to reach desired outcomes. Using high, direct heat to sear steak is simple enough, but what happens when you have a thicker piece that needs to go from direct to indirect so it doesn’t dry out? Instead of frantically fiddling with your grill’s temperature, which will take too long to adjust anyway, rely on multiple grill zones to keep you in control of temperature.
It’s a good idea to always have at least one direct zone of about 500°F–600°F and an indirect zone somewhere around 225°F (with in-between temperature zones as needed) as measured by a grill thermometer at grate level. That way, you can crisp up chicken skin at the end of an indirect roast or caramelize the sauce on ribs after tenderizing it with convection heat. Another great example is the tri-tip roast for Kelsey’s grilled tacos, which beautifully illustrates the core concept of multi-zone grilling.
“If I were to cook that over direct heat the whole time, the meat would cook from the surface-in,” Kelsey says. “So if you want a medium or medium-rare — that perfect pink center from top to bottom — you’re not gonna get with just keeping it over direct heat. You’d get some browning, then over-doneness, a little bit of pink in the middle, then over-doneness (at the top).”
“When we say a perfect medium or medium-rare, we’re really looking for the surface to be seared, caramelized. Then from top to bottom as you cut into that meat, we want it to be a nice, pink center for medium doneness on this tri-tip. By searing it for just about 5 minutes a side on that high heat in the direct area, and then moving it over to that indirect zone with a water pan acting as the baffle and reducing the temperature, that’ll give us the crust on the outside but let the internal temperature of the meat slowly rise up so I’m getting a nice, perfect top-to-bottom pink center.”
Cook More at Once
Being able to move meat from one zone to another is a huge advantage, but don’t let that stop you from using multiple zones at once for food that cooks at different rates. You’re free to use your grill just like you would your indoor range, whether that means setting burners to different temperatures or arranging charcoal in particular formations across the grill body (more on this later). For example, you can roast a whole chicken in an indirect zone while searing veggies over direct heat, or take on prime rib, grilled asparagus, and roasted potatoes all at once. Kelsey’s certainly not shy about it — after transferring her tri-tip from direct heat to indirect heat, she immediately gets her peppers and onions caramelizing in the direct zone.
Manage Flare-Ups with Ease
Few things are as frustrating as flare-ups, those leaping flames that threaten to overly char meat every time fat drips into the fire. Flare-ups can also turn into full-blown grease fires if unchecked, making them one of your greatest grilling enemies. But flare-ups can’t happen without fire, which is another point in favor of multiple grill zones. When fatty cuts like burgers make flare-ups unmanageable, simply transfer them to an adjacent indirect zone until the drippings stop. This won’t stop the cooking process, and once your meat looks ready for the open flame again, you can return it to the direct zone to continue grilling. In the same vein, you can pull meat off direct heat if the sugar-based BBQ sauce you’re trying to caramelize starts to burn.
Hold Food at Serving Temperature
Gather any group of 5 people for steaks, and you’re bound to receive requests for different doneness. Ryan likes his rare, Brock and Amy prefer medium-rare, Breana won’t settle for anything less than medium, and Hannah swears by well-done (we still love you, Hannah). Assuming the steaks are all the same thickness, that means you’re responsible for getting the timing just right on a variety of cooks with razor-thin margins of error. The solution? Designate a low-heat, indirect holding zone where you can stash the steaks as they finish.
Grill all the steaks at the same time over direct heat, moving them to the holding zone as they hit the correct internal temperature. Rare goes first, followed by medium-rare, medium, and finally well-done. The finished steaks sitting in the holding zone won’t continue to cook, nor will they cool past serving temperature — everyone’s cut will be properly cooked and still hot from the grill, no nervous meat juggling required. Though steak is an easy example, this holding technique also works well for times when sides and proteins don’t finish in lockstep.
Transform Your Grill
We’ve already mentioned how closing your grill lid with an indirect-heat setup essentially creates an oven, but it also allows the grill to function as a roaster and even a smoker! (Yes, smoking on a gas grill is possible.) This is the only way to successfully cook large cuts like roasts, loins, and whole birds, which would be well overdone by the time they cook all the way through if grilled over direct heat. Remember, convection heat is just as useful as hot-and-fast, radiant heat when properly applied.
How to Set up Multiple Grill Zones
Now that you understand everything that makes multi-zone grilling such an effective technique, let’s talk about how to actually put it into practice. The strategy differs depending on your grill type, its configuration, and what you’re cooking, but virtually every grill can house at least dual cooking zones. The only exceptions are gas and electric grills with only 1 burner or heating element; obviously, that limits you to just a single zone. A word of warning: because not all grills are created equal, establishing the most efficient set of cooking zones is an inexact science and will require some experimentation.
Multi-Zone Grilling on Gas & Electric Grills
For starters, how many burners or heating elements does the grill have? Most electric grills cap out at 2 elements, while we’ve seen gas grills featuring as many as 8 main burners. Whatever the number is, that’s the maximum number of zones you can create. Setting up zones on these types of grills is as easy as turning burner knobs to the desired level — for example, you might set the left-hand gas grill burner to high as your direct-heat zone, bring the middle 2 burners to low for an in-between area, and leave the right-hand burner off for your fully indirect-heat zone.
As we said above, dividing zones just right takes tinkering with your particular grill and understanding what you’re trying to cook. If you want to be extra confident that zones are contained to their respective burners with no heat spillover, look for a gas grill with heat-zone separators.
Multi-Zone Grilling on Charcoal Grills
A larger charcoal grill gives you more possible zones, but creating those dedicated areas is a little more difficult than what’s required for gas and electric grills. It all comes down to where you place charcoal, how much of it is in that area, and how you light the coals. Placement determines whether a zone is direct or indirect; more coals lead to higher temperatures, and vice versa; and lighting from the top-down promotes a low-and-slow burn, while bottom-up lighting results in a roaring fire.
The most common way to establish grilling zones in a charcoal pit is to bank lit coals to one side of the body, with the grates above serving as the direct zone and the rest of the cooking surface being indirect. Alternatively, you can fill the entire grill bed with charcoal and place a heat deflector plate (also known as a heat baffle) under the section of the grate you’d like to bathe in indirect heat. For multi-zone setups where you’d like charcoal banked to both sides or isolated in the middle, use a charcoal basket to ensure the coal remains where you want them. Again, it’s all about how the variety of cooking zones would best serve the food on the grill.
Multi-Zone Grilling on Pellet Grills
Despite their tremendous convenience, pellet grills actually don’t lend themselves to multiple zones quite as well as other grill types. The reason is twofold, and both are to optimize slow-and-slow smoking: pellet grills are largely designed to hold steady, even temperatures across the grates, and only a handful of models allow direct-flame grilling. The Weber SmokeFire that Kelsey used for her tri-tip tacos recipe is famously one of them, so her direct zone was taken care of by design.
To reduce temperatures on the indirect side for the second part of the cook, Kelsey used the SmokeFire Wet Smoke Kit to act as a water pan/heat deflector hybrid above the grill’s Flavorizer bars. Water pans in general are great for slower cooks because they add moisture to the grill, but the real benefit here is their ability to absorb heat to keep temperatures down in lower-heat zones. Though pellet grills are by and large engineered to be entirely indirect cookers, water pans and heat baffles are your best bet for multi-zone grilling when direct access to the flame is available.
Multi-Zone Grilling in Action
Whew, we’ve come a long way today! How about a few examples of masterful multi-zone grilling to get inspired? You’re already well-acquainted with how Kelsey used this technique to make delicious grilled tri-tip tacos, but it shouldn’t surprise you to see multiple zones used in some of our other Master Grillabilities. Atlanta-based pitmaster Rasheed Philips leaned heavily on multiple grilling zones for both his surf ‘n’ turf with compound butters recipe and his lemon Scotch bonnet pepper chicken wings recipe. In fact, dual-zone grilling is the most crucial part of his master’s guide to grilling crispy hot wings!
Now it’s your turn! Keep in mind everything we learned here, from the science behind multi-zone grilling to its many benefits and applications. Whether you’re attempting a 2-phase cook similar to Kelsey’s tri-tip, aiming to grill a protein and a few sides at the same time, or simply hoping to stop flare-ups in their tracks once and for all, this is a master skill that’ll serve you well every time you grill. Practice — and in this case, some experimentation — makes perfect.
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