While a freshly grilled steak may appear "bloody," the juices you see are mostly water. It's red because the water mixes with a special protein called myoglobin.

Myoglobin is found in mammalian muscles, where it stores oxygen. Blood contains a protein called hemoglobin, which binds to oxygen and carries it throughout the body.

When blood reaches organs and muscles, the oxygen transfers from hemoglobin to myoglobin. They perform the same function but store oxygen in different places.

They also share another thing in common: the color red. This is because they contain iron, which turns red when exposed to oxygen in the air.

The more myoglobin in meat, the redder it will appear. That's why meat from cows, who have high levels of myoglobin, is dark red.