Imagine you're just about to start shaping patties to make some juicy, homemade hamburgers when you notice a strange grayish-brown color inside the packaged ground beef. It might look concerning, but you likely have nothing to worry about. Let us explain.
The color of your ground beef starts at the molecular level. Meat gets its color from an iron-rich protein called myoglobin. There are three natural colors that myoglobin produces, depending on its exposure to oxygen. When oxygen interacts with myoglobin, oxymyoglobin forms, which makes meat appear bright red. Additionally, meat looks tan or brown if it contains smaller amounts of oxygen. If there's little to no oxygen present in the meat (like if it's vacuum-packed), it will appear purplish in color.
Since the center of packaged ground beef gets much less exposure to oxygen, it's unlikely to be red and more likely to have a brownish-gray color. Meanwhile, the outermost part of the product will have a bright red color because it's been exposed to more oxygen. In short, seeing these colors in these spots is typically normal and isn't a cause for concern.
There are a few simple ways to tell if your ground beef is rotting. A gray-ish tone in the middle of packaged ground beef may not indicate spoilage, but if the color is on the outside, the meat likely needs to be thrown out. White or blue hues in any region may also indicate mold, which means you should avoid consuming it.
A foul odor is also a telltale sign of spoiled meat. You'll usually notice the smell after removing it from its package. Texture is also a key indicator of decaying ground beef. Meat should be slightly firm and easily pliable when it's fresh. If the ground beef feels extra stiff or has become slimy or sticky, you may want to pass on it.