Have you ever bought ground beef that looked bright red in the package, only to find a grey or brown center when you opened it? Before assuming the store sold you spoiled meat, there’s something important to know: this color difference can be completely normal. Beef contains a protein called myoglobin, which changes color depending on how much oxygen it encounters.

When myoglobin is exposed to oxygen, it produces the familiar bright-red color often seen on the surface of ground beef. Inside the package, where oxygen is more limited, the meat can appear greyish or brown. This doesn’t automatically mean the beef is spoiled, nor does it prove the store deliberately misled you.

So, is grey ground beef safe to eat? It may be, provided it has been handled and stored properly. However, color alone cannot determine whether meat is safe. A sour or unpleasant smell, a slimy texture, damaged packaging, or improper refrigeration are warning signs. When in doubt, throw it out rather than tasting it to check.

To keep ground beef safe, refrigerate it promptly and use it within one to two days, or freeze it if you won’t need it soon. Cook it to an internal temperature of 160°F (71°C), as recommended by the USDA. Ultimately, red meat outside and grey meat inside isn’t necessarily a scam. The color difference often comes from normal oxygen exposure, but proper storage, freshness, and safe cooking matter far more than appearance alone.