When we have questions about tips and techniques for the home cook, we often turn to our friends at America’s Test Kitchen. Their crew has put in countless hours at the grill, so we asked Dan Souza, Editor-in-Chief of Cook’s Illustrated, for a guide to grilling. He talked with Managing Producer Sally Swift about different fire setups, proper use of grill vents, and why a small flare up can be a good thing. Try your skillful hand at the America’s Test Kitchen recipe for Grilled Mojo-Marinated Skirt Steak.

Sally Swift: I want to start with some of the mistakes that people make when they're grilling. Can you walk us through some of the common mistakes?

Dan Souza: What happens is a lot of people only grill when it's warm out. So, a whole year goes by and then they fall into some bad habits, or they never really knew the best practices. There's a few places where it’s not hard to do it right, but it's easy to go wrong.

The first one is if you're using a charcoal grill and you want to get it lit quickly. A lot of people reach for lighter fluid, and that seems like a good option. But in doing tests using lighter fluid and using the self-starting charcoal, we’ve found that a lot of it burns off, but you can still end up getting residual flavor from the lighter fluid, especially if you're cooking some really mild tasting food. We recommend moving away from lighter fluid. A great option is using a chimney starter. You can find them anywhere, they're not that expensive, and they last a long time.

Dan Souza Dan Souza Photo: America's Test Kitchen

SS: When you use a chimney starter, how do you know when the coals are ready? Should they be totally white? Are there flames coming off the top?

DS: You shouldn't see any flames when they’re ready. You’ll see flames and lots of smoke early in the process, then that will subside. When the coals are ready to go they should have a light dusting of white ash over the top.

SS: You have to wait.

DS: Yeah. If they are still black, they're not quite ready. You’re looking for that light coating of ash. You'll also see that they sink down a little bit into the chimney. That's when they're ready to go. If you dump them early you do potentially risk the fire going out or not heating very evenly.

SS: Can you walk us through the general fire setup?

DS: Let's start with charcoal where there are three main setups: single-level, double-level and concentrated. A single-level fire is where you have the coals poured over the entire surface in an even layer. That's good for when you want to char and cook at the same time. Think about smaller pieces of food like sausages or boneless skinless chicken breasts. You’re going to get some good char on the outside but you're also cooking through at a moderate rate.

A two-level fire is for when you have a bigger piece of food that you need to cook it gently to cook it all the way through the center, but you also want to sear it and get some char. What you want to do is pour the entire chimney into half of the grill, so you have these two zones: a very hot zone and a cool indirect zone. Start your bone-in chicken breasts on the cool with indirect heat and cook them until they're almost all the way cooked through. Then you simply move them over to the hot side to sear and char. That's a good technique for food that is larger where you need those two different heat levels.

The final setup is what we call our concentrated fire. Here, we corral the coals into a small area. Sometimes we use a disposable aluminum roasting pan with the bottom cut out of it; put a full chimney of coals in that and cook directly over it. This is for cooking foods like steaks and burgers where you want a big disparity between the outside and the inside. So, for a steak we're looking for a good sear on the outside with tons of char; on the inside we want to be about 125 degrees or medium-rare. We want that disparity.

Fire up your grill and make this America's Test Kitchen recipe for Grilled Mojo-Marinated Skirt Steak. Photo: America's Test Kitchen

SS: Tell me about the lid. When do you use the lid and when don’t you?

DS: To lid or not to lid? That's a big question when it comes to grilling.

SS: I know it’s a basic question, but one that stumps many people.

DS: It is a great question and it does matter. If you're working on a gas grill, generally speaking they don't have the output of a charcoal grill. So, a lot of times we recommend keeping the lid down when you're using a gas grill. You never want to light a gas grill with the lid down because it can trap gas and cause some problems. Light it with the lid open, but for the most part when you're cooking with a gas grill you want the lid to be down. That's going to make it hotter inside.

The opposite is true when you're working with a charcoal grill because that's all about airflow. If you have the lid off of a charcoal grill you have a lot more air rushing through there, so it's going to burn even hotter. If you're cooking something like a burger and steak, where you want a really hot fire, cook with the lid off. If you are cooking something lower and slower, such as barbecues or indirect cooking a roast that you're going to sear, you want to cook with the lid on.

With charcoal, if you have the lid on it’s going to slow things down. This leads to another good point which is grill vents. I think a lot of people are confused as to what to do with grill vents and what they're used for. They actually have a huge impact on the temperature of your grill. As I mentioned, airflow is what controls your fire with a charcoal grill. The grill vents are located on the bottom and the top of the grill. If you have them completely open you're getting more air through and your grill will be hotter. If you start to close them down, maybe halfway or three-quarters of the way, you will cool the fire down. If you close them all the way you risk putting the fire out because there's no more airflow.

SS: And you should clean out the ash from the bottom of the grill.

DS: Yes. Cleaning is a big thing and it definitely starts with the ash bucket. If it's jammed up it's going to restrict airflow. If you have a grease trap in a gas grill, you want to open it up and look in there to make sure that it's cleaned out. If you have a lot of grease buildup and you have a fire in there, it can cause a big grease fire that can be dangerous – and definitely inconvenient.

SS: I have a question about when you want something really charred on a charcoal fire. I've seen people keep squirt bottles of oil next to them and squirt the flames to get the flames up. Does that work?

DS: That's a dicey thing to say. There's some danger in that you're putting oil on a fire, and it's very flammable. But, even beyond that it's not really a great idea. When you see a burst of flame on a grill like that we call it a flare up. And a little bit can be good. If you have a burger cooking over coals and a bit of fat drips down setting off a tiny little flame, that's vaporizing the oil and the juices. A lot of that flavor can come up and actually stick back to the food providing a nice grill flavor.

We do have a technique that I will mention for when we're cooking beef tenderloin on the cooler side of the grill. On the hotter side we have one or two pieces of bacon that we've scrunched up on a skewer sitting over the fire. As that starts to cook and render, you get those little drops of fat and juices that flare up and do provide a smoky flavor to the tenderloin. But I would say that's the exception to the rule.

America's Test Kitchen
The Splendid Table frequently visits with the test cooks at America’s Test Kitchen to discuss a wide range of topics including recipes, ingredients, techniques and kitchen equipment.