# Why does ground beef get darker? **URL:** \ **Category:** Cafe Society\ **Created:** [March 14, 2010, 7:51am UTC](https://boards.straightdope.com/t/why-does-ground-beef-get-darker/532431 "2010-03-14T07:51:21Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Leaper](https://avatars.discourse-cdn.com/v4/letter/l/4bbf92/32.png) [@Leaper](https://boards.straightdope.com/u/Leaper)\ **Post date:** [March 14, 2010, 7:51am UTC](https://boards.straightdope.com/t/why-does-ground-beef-get-darker/532431/1 "2010-03-14T07:51:21Z")
So I took out and thawed overnight a pound of ground beef, still in the original packaging, that I’d had in the freezer for about six weeks. It was very dark brown; it made it harder to tell when it was cooked. Why does it do that? ---
**Author:** ![Leaper](https://avatars.discourse-cdn.com/v4/letter/l/4bbf92/32.png) [@Leaper](https://boards.straightdope.com/u/Leaper)\ **Post date:** [March 14, 2010, 8:55am UTC](https://boards.straightdope.com/t/why-does-ground-beef-get-darker/532431/2 "2010-03-14T08:55:29Z")
(Hmmm… Now that I think about it, considering the color issue, how confident can I be that I did indeed cook it well enough? I cooked it as crumbled ground beef to mix into something colored, so that may not be a lot of help, and there was a while, especially at the beginning, where I really wasn’t watching it, since I was washing a few dishes and such. It was at the high side of medium for I don’t remember how long, but even with 15% fat, there was surprisingly little to drain: less than two and a half tablespoons [as in the utensil].) ---
**Author:** ![Tarwater](https://avatars.discourse-cdn.com/v4/letter/t/9de0a6/32.png) [@Tarwater](https://boards.straightdope.com/u/Tarwater)\ **Post date:** [March 14, 2010, 9:10am UTC](https://boards.straightdope.com/t/why-does-ground-beef-get-darker/532431/3 "2010-03-14T09:10:26Z")
Ground beef requires oxygen before it turns the reddish pink color most people associate with freshness. If it doesn’t have that it’ll be a darker, almost gray color. Your situation sounds fairly normal. You can keep ground beef in the freezer for 4-5 months before it actually spoils. ---
**Author:** ![Barking\_Dog](https://avatars.discourse-cdn.com/v4/letter/b/ccd318/32.png) [@Barking\_Dog](https://boards.straightdope.com/u/Barking_Dog)\ **Post date:** [March 14, 2010, 3:22pm UTC](https://boards.straightdope.com/t/why-does-ground-beef-get-darker/532431/4 "2010-03-14T15:22:57Z")
It has to do with why red meat is red. Red meat (such as cow or horse) is red because it is full of myoglobin, a protein chockful of iron (someone probably needs to correct me on what _exactly_ myoglobin _is_, but still lots o’ iron). Thanks to that iron, myoglobin, like its cousin hemoglobin (the stuff that makes your blood red) holds on to oxygen so the cells can function. As the meat decays (sorry, even in the freezer it decays) the myoglobin releases its hold on the oxygen molecules, and without the oxygen it turns that grayish-brown colour. In a way the meat is rusting. At least that’s the way I understood it. And after six weeks in the deep freeze, your meat is perfectly safe, in case you were worried. Meat kept in the freezer is safe and tasty up to six months. However it does seem a bit weird to me that it should have browned like that so quickly in the freezer. It might be safe to check if your freezer isn’t running a little hot, or the butcher didn’t sell you an old bit of beef. But that’s just my opinion. I could be wrong. ---
**Author:** ![Leaper](https://avatars.discourse-cdn.com/v4/letter/l/4bbf92/32.png) [@Leaper](https://boards.straightdope.com/u/Leaper)\ **Post date:** [March 14, 2010, 9:42pm UTC](https://boards.straightdope.com/t/why-does-ground-beef-get-darker/532431/5 "2010-03-14T21:42:12Z")
Quickly? How long is it “supposed” to take if frozen?