Barbecue and grilling are rife with old husband’s tales handed down for generations. But now we have science and curious cooks who have questioned these shibboleths. In my new book, Meathead: The Science of Great Barbecue and Grilling, I dispel scores of these myths.
Here are some of the hardest to kill that won’t go away:
I cannot understand why so many talented cooks parrot this nonsense. You absolutely positively definitively without doubt no way no how cannot tell anything about the temperature of a grill by holding your hand over the grate and counting "1001, 1002, 1003" until your palm starts to smoke. Each of us reacts differently to heat and the heat 1 inch above the grate can be significantly different than 6 inches above.
You want a grill that has enough cooking surface that you can set up two heat zones: one side hot, one side not. One side is heated by direct radiant heat, the other by indirect convection heat. On a gas grill, turn the burners off on one side. On a charcoal grill, push all the coals to one side. Now you have temperature control.
The best technique for thicker cuts of meat is called the reverse sear. (It works indoors, too.) For all but very thin foods, you want to start cooking on the indirect side and slowly warm it and bathe it in smoke, an elegant seasoning you can’t get from your spice rack. By slowly warming the meat, it cooks evenly throughout and enzymes kick in to tenderize the meat.
But you do want a darkly caramelized, crisp crust, so the trick is to move the meat from the indirect side to the direct radiant heat side about 10 to 15°F before it hits the target temp, and sear the snot out of it with the lid open. This concentrates all the heat on one side, browning the surface. Leave it facing the fire for only a minute or two so not too much energy is absorbed. Then flip it and let it cool on the top side while the bottom browns. Flip flip flip every minute or two until the exterior is dark brown, and the interior is the target temp. (It is far easier to hit a slow moving target than a fast moving one.) Try it on a thick steak or chicken or even a baked potato!
Meat is about 70% water and most of that is locked in thousands of long thin muscle fibers. Heating meat always squeezes out juices. Some juices drip off during cooking and some evaporate, and nothing can stop the process. Hear that sizzle? That’s water on hot metal.
Although searing browns and firms up the surface, which makes it feel and taste great, it does not somehow weld the fibers shut and lock in the juices. In fact, the surface gets crusty mostly because it has dried out due to high heat, and searing, which needs high heat, causes water to evaporate. Doing side by side tests of seared and unseared meats cooked to the same temp, the seared meat weighs less. And any experienced griller will tell you that even after searing, juices pool on the surface.
Marinades are primarily a surface treatment, especially on thicker cuts. Meat is a protein sponge saturated with water. There's not much room for any more liquid in there. As for the flavor molecules, salt gets electrically charged when wet and they can split up and penetrate deep into meat. But sucrose, garlic, pepper, etc. are huge molecules that can’t get past the cracks and pores on the surface. Even overnight they rarely penetrate more than ⅛ inch. That’s a lot on a thin skirt steak, but not much on a double wide pork chop or a chicken breast.
Meat juices are simply water tinted pink with a protein named myoglobin, and myglobin is never found in the blood stream. If it were blood, it would be dark red, the same color as your blood, and it would coagulate. Every time we call it "blood", somewhere a teenager becomes a vegetarian. Let's just call it "juice" from now on, okay?
If you believe it, you could end up badly overcooking your poultry or worse, spend the night on the toilet, or worse still, spend it in the emergency room. The meat and juices in chicken, turkey, and even pork are water that is colored pink by the protein myoglobin. When myoglobin is cooked, its structure changes and the altered molecules no longer appear pink. The question is, at what temperature does myoglobin change color?
Turns out there is no fixed temperature because other factors come into play, especially the acidity (pH) of the meat. Muscle pH differences are a function of genes, pre-slaughter stress conditions, and climate. So the color of the juices can remain pink long after the meat is pasteurized and safe by cooking to 160 to 165°F or they could run clear before the meat is safe.
It is also common to see chicken meat near bone ends turn purple, even when cooked to a safe temperature. The thigh below was cooked to 180°F as measured with a precise thermometer. Believe it or not, it is safe to eat. Purple bones are more common these days because modern chicken breeds are usually only 7 weeks at slaughter and the young bones are still porous so the marrow can be visible or leak out and that's where blood is made. Even though the bird is cooked properly, the purple remains. Bottom line: Color is not a reliable guide in any meat. Only temperature is.
It is widely accepted wisdom, appearing in practically every barbecue book ever written: "If you're lookin', you ain't cookin'." Many say that for long cooks like pork butt or ribs, or beef brisket, you add 15 minutes each time you peek.
But that’s not how it works. Warm air in a grill cooks the outside of the meat, but heat built up in the outside of the meat is what cooks the inside of the meat. Since meat is mostly water and water holds heat better than air, opening the grill may cool the air in the grill, but the meat barely notices. My associate, the physicist and food scientist Professor Greg Blonder of Boston University, did tests on chicken cooked on a charcoal, gas, and pellet grills. He placed thermometer probes in the air, just under the skin of the chicken, and in the center of the breast. Opening the lid drastically reduced the air temp, but had a very small impact on the surface temp and no impact on the temp in the center of the meat. So a minute here or there to baste the meat, rotate positions for uniformity, or to insert a thermometer, is time well-spent. No harm, no fowl foul.
Actually, the opposite is true. Billowing white smoke may be great if you’re electing a Pope, but a faint wisp of blue smoke is the holy grail of low and slow pitmasters. It is barely visible because it is made of tiny invisible particles and gases made by small hot fast burning fires. White smoke comes from smoldering wood starved for oxygen. Blue smoke makes food taste better than white smoke. So if your wood chips burst into flames, don’t sweat it. That’s cool blue happening.
Grill manufacturers often tout their grill’s BTUs (British Thermal Units/hour), a measure of energy. But the BTU rating is not indicative of the heat a grill can generate. BTU is derived from a calculation based on gas pressure, the size of the opening in the gas valve, and the type of gas. The more BTU, the more fuel used, not the higher heat. If you were shopping for a really fast car, the miles per gallon would not be a useful guide to how fast the car goes. It's kinda like that.
So many grill books say to swab the cooking grates with oil to prevent sticking. Sometimes it works, sometimes it doesn’t. It depends on the temperature of the grates. According to Dr. Blonder:
“Metal grill grates, even shiny clean ones, are not really smooth. Under a microscope, there are numerous scratches, pits, valleys, and ridges. The compounds in food are much colder than the grates. When the two meet, a bond forms between them. If you oil the grates when the temp is below the smoking point, the oil actually does coat the grates and helps release protein and fat. But if you keep it above the smoke point, the oil cracks, smokes, and carbonizes almost instantly. The carbon and smoke don't taste good, and the dry, uneven carbon layer simply makes sticking worse.”
The best way to keep food from sticking is to oil the food. The cold food keeps the oil from burning and cracking.
This article originally ran in May of 2016.
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