Here is a picture of raw "reserve beef for stew" that we just bought at our local (nation-wide chain) supermarket:

enter image description here

Where do these green streaks on the meat come from ? Is it normal and safe to cook it ? It is not really very good-looking...

They appear on most of the pieces.

  • 4
    The only things I can think of are bile or some sort of mold or bacterial growth. If the gall bladder was ruptured during butchering, bile could have spilled on the meat. That would be harmless, but having no way to be sure which it is, I wouldn't eat it. I would take it back to the store. Commented May 11, 2014 at 23:17
  • 1
    Reserve beef for stew is not an appetizing name, is it? Safe or not I wouldn't want to eat it!
    – GdD
    Commented May 12, 2014 at 8:16
  • 1
    Unless I knew EXACTLY what it was, I would not like to try eating it!
    – user42531
    Commented Jan 16, 2016 at 2:34

1 Answer 1


You should be aware that it is perfectly normal for meat to oxidize and become grey in color. In this case, it is still safe, provided it has been stored properly.

I cannot be completely sure that this is the cause based on just your picture. If you have seen the oxidation-grey meat I am referring to and know this is not the same, then this is something different, and possibly dangerous (although Carey Gregory's bile hypothesis has some merit).

But nowadays supermarkets try to hide this process, afraid that their meat will look unappetizing to customers. They package meat in individual containers with low oxygen content (which also has the benefit of keeping it safer). If they still sell raw meat from the display, they only keep a small amount of display, preferably not pre-cut, and stacked tightly, so there is little surface exposure to oxygen. I've also heard that they use nitrites on the surface to prevent the grey-green tinge, but I am not completely sure this is true (it could be illegal, or the amount necessary to prevent the color change could be high enough for the meat to start feeling cured).

So, if you have never seen the grey meat I refer to, this could very well be an example of it. If

  1. you stored the meat properly
  2. the green surface is not slimy (at least, not slimier than the normal parts of the raw meat)
  3. the green surface doesn't smell unusual
  4. there is no texture difference, just the discoloration

chances are that this is not dangerous. You could still decide to be extra safe and discard it (nobody can prove that this is nothing bad), or you could accept the oxygenation explanation and eat it. Or maybe show it to a butcher or an older relative who was used to shopping meat before modern technology made oxidized meat surface a rare sight.

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