For years, I believed the same thing most people do.

Cut into a rare steak, watch that red liquid spill onto the plate, and assume it’s blood.

It certainly looks like blood.

It’s red, thin, and seems to flow straight from the meat the moment the knife goes in.

But the truth surprised me.

That red liquid is not blood at all.

The real culprit is something called myoglobin, a protein found in muscle tissue that helps store and transport oxygen. When meat is exposed to air, myoglobin reacts with oxygen and turns the bright red color we associate with fresh beef.

The amount of myoglobin varies depending on the animal and the muscle. That’s why beef is darker than chicken breast, and why turkey legs appear darker than turkey breast meat.

The reason rare steak appears “bloody” is because the meat still contains plenty of moisture. Since beef is made up of roughly 70% water, the juices mix with myoglobin and create a red liquid that closely resembles diluted blood.

Actual blood is removed from animals during processing long before meat reaches grocery stores.

Another surprising fact?

Fresh beef is naturally more purple than red. The bright red color seen in supermarkets develops when the meat is exposed to oxygen during packaging. As it ages, oxidation causes the meat to gradually turn brown.

So the next time someone says they like their steak “bloody,” you can share a surprising fact:

What they’re really enjoying is a mixture of water and myoglobin—not blood.

And for many people, that changes the way they look at steak forever.