Why We Don't Need Grill Marks, and Why You Should Flip Often
"Constantly turning burgers and hot dogs is a great way to avoid interaction with others." David Letterman
All the grocery store advertisements, all the restaurant ads, all the grill ads show beautiful steaks and burgers with cross hatched grill marks. Restaurants can even buy chicken premarked with grill marks that they can microwave and serve, and cooking mags and cookbooks teach readers how to get great grill marks.
Look at the ribeyes numbered 1, 2, and 3 on this page. Don't ribeye 1 & 3 create a Pavlovian response? Yes, that's what grill marks do. But I'm here to tell you, ribeye 2 will taste the best.
Why grill marks are overrated (most of the time)
When it comes to meats, and many other foods, the goal is golden to brown color on as much surface as possible. Dark brown crusts on grilled meat are the most flavorful part because dark brown is the result of changes in the chemistry of the meat. Called the Maillard reaction and caramelization, browning occurs when heat changes the structure of amino acids, proteins, and sugars, creating hundreds of new really tasty compounds. We call that searing, and the result is a crust that to many of us is the highlight of the meal. When it comes to most foods, brown is beautiful. Black is not. Tan is not.
Chefs know this. The spectacular 30 day aged USDA Prime strip steak at the top of this page is from David Burke's Primehouse in Chicago, my favorite steakhouse. Chicago Magazine rated Primehouse the best in Chicago, a town that knows a thing or two about beef (photo courtesy of Anna Knott of Chicago magazine).
Those beautiful grill marks are merely superficial branding, just coloring on the surface -- like the freckles on Lindsay Lohan, cute, but lacking substance -- unlike the deep rich sear that delivers max taste and texture in ribeye 2.
The steak with the mouthwatering cross hatches has perhaps 1/3 of the surface fully browned, but the diamond shapes between the grill marks remain tan, boring, well done meat, whose potential is unrealized, like Superman without a phone booth, like Gehrig without a bat, like Chopin without black keys.
Worse, if you're not careful, grill grates can scar your meat with black stripes of chalky carbon that tastes like burnt toast, and might contain hazardous Heterocyclic Amines, like ribeye 3.
That's one of the reasons that great steakhouses use broilers where the flames are above the meat. That way they can get brown all over. That's why grill marks don't make me salivate. I want brown all over.
Here's what's going on.
Not all heat is the same. As I describe in my article on the thermodynamics of barbecue, cooking on a grill involves radiation, convection, and conduction. Conduction is when the metal grates are in direct contact with the food. It is the fastest way to transmit heat to meat. Radiation is the heat carried by infrared light emanating from coals or gas burners directly below the food. It is second fastest method. Convection is the warm swirling air if the meat is not directly exposed to flame. It is the slowest method. Conduction cooks faster than radiation or convection.
Metal grill grates transmit heat much better than air because they have so much more mass. Air is really a better insulator than conductor. That's why styrofoam is filled with air. That's why you can put your hand into a 300°F oven for several seconds, but touch 300°F grill grates and you're blistered in an instant.
OK, there are some occasions when you do want grill marks
When you have thin foods like shrimp, skinny chops, skirt steaks, asparagus, and bell peppers, it is hard to get the exterior browned before the interior is overcooked. This is when you want grill marks. That conduction cooking will develop part of the surface in a hurry, leaving the inside tender and juicy. So on foods that are less than 1" thick, grill marks actually are good. But on thicker foods, I want all over browning.
How to get the perfect Maillard sear
So how do you get the perfect all over Maillard brown sear? Cook the meat in a cast iron pan with a thin coat of oil.
OK, so you want that grilled smoky flavor. Then don't use a pan. Go the exact opposite direction. Start with a piece of meat that is more than 1" thick and use cheap thin wire grill grates in order to allow the browning to come from direct heat radiation and allow the drippings to vaporize and flavor the meat. But don't let the meat sit on the grates so long they burn. Move the meat around a lot so the thin grates won't make marks, and you get the all over mahogany color you want.
Say what? Why not use cast iron grates? Aren't they the best?
Cast iron is really heavy and holds a lot of heat so it will give you super grill marks. But it doesn't do anything for the interstices, the diamond shaped tan gaps between the grill marks. So you end up with the rich dark sear on only 1/3 of the surface. Believe it or not, cheap thin wire grates are my first choice although I often use a cool product called GrillGrates and I turn them upside down. Click here to read my reviews of popular grill grates and how to clean them.
Then, flip the meat a lot.
Debunking the "flip just once myth"
Say what? All the books say to flip your meat as little as possible!
Not any more. If you flip more often, you get better flavor, more even color and doneness, and less cooking time. Among the advocates of frequent flipping are Harold McGee, author of On Food and Cooking: The Science and Lore of the Kitchen, J. Kenji Lopez-Alt of SeriousEats.com, Nathan Myhrvold, editor of the landmark six-book set Modernist Cuisine: The Art and Science of Cooking, and the AmazingRibs.com science advisor Prof. Greg Blonder, all culinary scientists of serious consequence.
Here's what McGee says "If perfect grill marks are necessary [flip] once or twice. If texture and moistness are more important, then flip every minute. Frequent turns mean that neither side has the time either to absorb or to release large amounts of heat. The meat cooks faster, and its outer layers end up less overcooked."
Lopez-Alt decided to test the theory. He made a dozen 1/2 pound burgers and cooked them in a steel skillet heated to 450°F. He flipped some often, every 15 seconds in some cases, and others he flipped only once. He took them all to an internal temperature of 125°F (medium rare and well under the USDA recommended safe temp) and then rested them for five minutes at room temp. Sure enough, the patties that were flipped more often cooked in 2/3 the time, the edges were more brown, and the color was more even top to bottom. The single-flip burgers got a little darker on the outside, but had a thicker layer of well done and overcooked meat under the surface, up to 50% of the thickness! That number fell to 40% when flipped every minute, 35% when flipped every 30 seconds, and 30% when flipped every 15 seconds.
Here's what is happening. When the meat is exposed to contact with the hot pan it absorbs heat a lot faster than when exposed to hot air, which is not a good conductor. The molecules on the meat's hot surface get excited and start moving around a lot raising the temp of the slower molecules closer to the center. Then, when you flip the meat, the surface cools a bit immediately so it is less likely to burn when you flip it towards the heat, but the molecules below the surface, are still jumping around and inviting their buddies to dance along with them. The same thing happens when the meat is over a hot flame. The process is essentially the same as when you are cooking with a rotisserie. Blonder points out that "Many famous steak houses cook steaks in two-sided broilers that subject meat to direct flames from above and below- truly the gates of hellicious browning."
I have played with the process a lot and indeed, flipping every minute or so give me the best crust, and least overcooked meat beneath the surface.
I asked the AmazingRibs.com science advisor, Prof. Greg Blonder, what he thought of the concept. "Flipping every 15 seconds is just barely OK. If you flip that fast, the crust does not form because each time you flip you have to steam off any exuded water before browning can start. This takes more than 15 seconds. I think the better approach is to keep the meat flat for at least a minute, then flip. Of course, on a grill the steam quickly exits between the grates, so you can flip faster than in a frying pan."
Reverse sear poultry and anything thicker than 1"
The only problem with all of this is that, on poultry or steaks and chops more than 1" thick, you need to do one more thing. Reverse sear.
So far we have been concentrating on the surface of the meat. But if you have a chicken leg or thigh, it has to be cooked to 165°F to be safe. A steak is perfect medium rare at about 130°F to 135°F. By the time you get the chicken up to temp, that fatty skin is as black as the Interstate. Ditto for thick steaks and chops. So the technique is to reverse sear. Cook the inside of the meat first by putting it into a convection heat zone where it is not directly exposed to high heat. Do this by setting up your grill into 2 zones, one direct, one indirect. Start a thick steak on the indirect side at a low temp and warm it slowly until the interior is about 20°F below your desired temp, and then move it over the direct heat to sear. That's right, you cook the inside and the outside differently, and you sear at the end of the cook, not the beginning. The process is called reverse sear and you can read more about by clicking here.
Now keep in mind, a lot depends on the type of meat, its thickness, and the heat of your grill, but if you understand these concepts, you can amp up your grilling: Shoot for a uniform all over deep golden to mahogany color, just this side of black, and to get there use either thin wire grates with the meat right above the heat, or a flat surface like a griddle or the back of GrillGrates, and turn often. For thick cuts of meat and poultry, reverse sear.