Cut into a perfectly cooked rare steak and you’ll often see red liquid seep onto the plate. For many people, this instantly triggers the thought: “That’s blood.” But this belief is one of the most common food mythsand it’s completely wrong.
The red juice in rare steak is mostly water mixed with myoglobin, a protein found in muscle tissue. Myoglobin’s role is to store oxygen in muscle cells, and it has a naturally red pigment. This is what gives raw beef—and rare beef—its red color.
During cooking, heat causes muscle fibers to tighten and release moisture. That moisture combines with myoglobin and flows out of the meat, creating the red or pink liquid people often mistake for blood. In reality, nearly all blood is removed from an animal during processing, long before the meat ever reaches the butcher or grocery store.
As steak cooks longer, myoglobin changes chemically due to heat. This causes its color to shift:
Red in rare steak
Pink in medium steak
Brown or gray in well-done steak
That’s why well-done steaks appear drier and darker—they’ve lost more moisture, and the myoglobin has fully changed color.
Interestingly, the presence of this juice is often a sign of juiciness and tenderness, not undercooking. Many chefs value it because it helps keep the steak flavorful rather than dry.
So the next time someone hesitates at a rare steak because of the red liquid, you can confidently explain: it’s not blood at all. It’s simply protein-rich muscle juice, and it’s a natural part of what makes steak delicious.
