That reddish puddle in a package of steak looks like blood, but it’s mostly water that has seeped from the meat, tinted by a protein called myoglobin. Meat scientists call the liquid purge. It’s a normal result of cutting, packaging, and storing steak—not a sign that something went wrong.
Why is it red?
Myoglobin helps muscle cells hold oxygen and gives beef much of its color. As moisture escapes from a steak, it carries some myoglobin into the package. Most of the animal’s blood is removed during slaughter, so the liquid pooling under your steak isn’t blood. Michigan State University Extension explains how myoglobin also changes the color of meat: vacuum-packed beef can look purplish, then turn brighter red when exposed to air.
You may notice more purge after thawing a frozen steak. Ice crystals can damage muscle cells, making it easier for moisture to escape. A little extra liquid, by itself, doesn’t tell you whether the steak is safe to eat.
What should you do with it?
You can discard the liquid with the packaging and pat the steak dry before cooking. But treat purge like any other raw meat juice: keep it away from foods you won’t cook, and wash hands and surfaces it touches. Don’t judge safety by redness alone. The USDA notes that an off odor or a sticky, tacky, or slimy surface can be signs of spoilage.
For cooking, use a thermometer rather than the color of the steak or its juices. FoodSafety.gov recommends 145°F (63°C) for beef steaks, followed by a three-minute rest. The takeaway is simple: red liquid may be surprising, but it’s an ordinary part of packaged meat—and one more everyday mystery behind our food facts.