One persistent cooking adage is that if you pierce a chicken and the juices are clear, the meat is done. But is this oft-cited “rule” actually true?
A chicken breast is done when it reaches 160 degrees, while thighs are done at 175 degrees. But when we cooked whole chickens, in one case the juices ran clear when the breast registered 145 degrees and the thigh 155 degrees—long before the chicken was done. And when we pierced another chicken that we’d overcooked (the breast registered 170 degrees and the thigh 180 degrees), it still oozed pink juices.
Here’s the scoop: The juices in a chicken are mostly water; they get their color from a molecule called myoglobin. When myoglobin is heated, it loses its color. So there’s some good reasoning behind the adage. The problem is that the exact temperature at which this color change occurs varies depending on a number of factors (primarily the conditions under which the chicken was raised and processed). The best way to check for doneness? Use a thermometer.