For people who prefer their steak well-done, there's nothing quite as gross as seeing the blood drip out of a rare steak. But good news, that pink liquid isn't actually blood. Fox reports the liquid present in the meat packaging, and the stuff that trickles out after the meat is cooked is actually myoglobin, a protein that's only found in muscle tissue. Myoglobin carries oxygen through the muscle and contains a red pigment, which is why muscle tissue is red. As a steak is cooked, the myoglobin darkens, which is why the more “well-done” the meat is, the more grey it looks. Interestingly, commercial meat packers sometimes treat raw steaks with carbon monoxide to “lock” in the myoglobin and keep it looking a nice, fresh red color.