Debunking the Myth: Why It’s Not Blood
Contrary to popular belief, the liquid in your steak is not blood. During the slaughtering process, most of the animal’s blood is drained out. What remains in the meat is primarily water (about 75% of meat’s weight) along with proteins like myoglobin. When you see that red juice pooling on your plate, you’re actually looking at a mixture of water and myoglobin released from the meat’s cells during cooking.
Why the Misconception?
This misconception likely stems from the fact that both blood and myoglobin are red due to their iron content. However, while blood carries oxygen throughout the body via hemoglobin, myoglobin only stores oxygen in muscle tissue. This is why the ‘red juice’ in a rare steak has no connection to blood.
What Happens to Myoglobin During Cooking?
The color of meat changes as it cooks due to transformations in myoglobin:
Raw Meat: Myoglobin is in its natural state, and the meat appears deep red or purple.
Rare or Medium-Rare: As the steak heats up to 120-130°F (49-54°C), the myoglobin starts to release water, resulting in the red or pink juice that’s commonly seen in rare steaks.
Medium to Well-Done: At higher temperatures, the myoglobin’s iron oxidizes, turning it brownish. This is why well-done meat has a grayish-brown color and drier texture.
The amount of myoglobin remaining in the meat determines how red or pink the juices are. As the internal temperature rises, myoglobin is denatured, and the red color gradually disappears, leaving a clear liquid instead.
Why Does Red Meat Contain More Myoglobin?
Different types of meat contain varying amounts of myoglobin, which affects their color and texture:
Beef: Has a high concentration of myoglobin, giving it a dark red color when raw.
Lamb: Contains slightly less myoglobin than beef but still has a distinct red hue.
Pork: Classified as red meat but has a much lower myoglobin content, so it appears lighter.
Poultry: Chicken and turkey breast have very little myoglobin, making them pale in comparison to red meats.
This difference is why a rare steak appears red and juicy, while rare chicken would not have the same appearance.
