Do you recognize this Chemical above? Probably not!
It actually happens to be what I call one of the biggest misconceptions in food and cooking. How many times have you said or heard someone say “My steak is still bleeding” or “I like my Steak Bloody”? What if I told you that in most cases it is not even blood (obviously depending on the cut). When you think about it for a while it actually makes sense! Where does the blood circulate in your body? Your muscles or your veins? Obviously your veins! So if you are eating a piece of animal muscle why should it be any different? So when you think of it logically then it makes sense that the piece of rare steak you have in front of you is not actually bleeding nor does it contain any blood.
The Exception to this rule is generally the tougher cuts of meat which need to be cooked for long periods of time, these are the cheaper cuts of meat which contain veins and residual blood, which is still only in the veins and not in the meat. For best results in these cuts you will need to extract as much of the blood from the veins by using running water or leaving them overnight in ice water.
The thing which seeps out onto your plate is actually called Myoglobin, this is the protein thats responsible for giving meat its red color and actually delivers oxygen to your muscles in live meat. See the wiki link below to learn more.
As you can see in this Kobe pictured above, it is perfectly red but totally dry (so there goes the blood theory as if there were blood it should be flowing out. The reason meat becomes grey when cooked to well done is because the Myoglobin is Oxidizing and the molecules change their format, the Myoglobin ends up leaving the meat with the expelled water which leaves the grey meat.
So the next time you have a difficult guest in your restaurant who insists there meat is still bleeding kindly correct them that it is not in fact bleeding but seeping one of it’s proteins which has nothing to do with blood. Or if they are really difficult just do as I do, sign their bill and throw them out of your restaurant, there not worth the stress