Did I eat bad meat?

Like a lot of folks, my dinner tonight consisted of “random leftovers” – e.g., stuff that’s been sitting in the refrigerator for the last few days. One of these dishes was the last bits of my mom’s roast beef; she first cooked it about five days ago, and my wife and I have been eating portions of it in the interim.

Well, while polishing off the last of it tonight, I noticed that a few pieces had a greenish-blue “shimmer” on them. The effect reminded me of fish scales for some reason, and you could only see the color if you held it to the light at a certain angle. Not wanting to take a chance of catching something, I tossed it instead of eating it. Still, I had eaten several other pieces earlier…

So what did I see on those slabs o’ beef? The beginning of a bacterial culture? A mutant form of gravy? Or just the natural side-effect of cooking beef to begin with? I haven’t felt ill, but I am curious as to what that was… anyone care to venture a guess?

I’m not sure if it’s the same thing, as I’ve never seen it on roast beef, but it’s quite common to have that shimmery fish scale look on leftover corned beef, as early as the day after it was originally cooked. It definitely looks odd, but I’ve never had a problem with eating it, and have never really worried about it, either, because it is still “new”, as far as leftovers are concerned.

I’m not sure what to tell you, other than, if you don’t end up sick within the next 12 hours, then the meat was fine.

I will say that, when I worked in health care, the rule of thumb for leftovers was “nothing over 3 days old”, and I’ve followed that rule at home, ever since, just as a precautionary measure.


I’m not prepared to give the straight dope on what causes that iridescent sheen, but I agree with VDarlin that it isn’t a toxin of any type. I have in fact seen it on roast beef (cold, sliced, in a sandwich store).

How did it taste?

rjung - if you had been using Windows, and not that Mac crap, this never would have happened.
Just kidding.
Seriously, if meat is bad, you can usually tell. The smell and/or taste would put you off well before you ever swallowed. Meat goes bad fast, and as bad bacteria sets in, it gives off an unpleasant odor - you would notice.

kaylasdad99, it tasted the same as all the other leftover roast beef I’ve ever had. Gravy was a bit thin, but otherwise fine.

Boscibo, now that you’ve mentioned it, that sheen actually reminded me of the Windows XP “luna” scheme… uninspired and slightly sickly-looking. :wink:

From the USDA:

The meat scientists at Ohio state go into greater detail, but also state that “iridescence is a natural occurring factor, and does not effect the quality or the palatability of the meat.”

It’s not always true that meat contaminated with dangerous levels of the bacteria that can cause food poisoning will have a bad smell; generally this is the case if the food is left unrefrigerated (only really because it will spoil quite quickly), but in colder conditions, certain types of bacteria prosper more than others; in this case, it’s possible to have dangeously high populations of harmful bacteria and little or no unpleasant smell because the food poisoning bacteria are not necessarily the ones responsible for the odour.