I never buy pre-ground beef in the supermarket. I always select a piece of meat (bottom round, top round, chuck steak, etc...whatever is on sale) and have them grind it up for me.
Aside from freshness, the big reason is I can then cook my burgers medium rare and not have the e-coli issues that follow along with pre-ground beef that may or may not be sold at the supermarket. When you are getting ground beef from the processing plant, you run the risks of contamination because of all the fecal matter that is cleaned from the carcass.
Anyway, here's my question to you meat experts. When I get the roast ground up and I get it home, most times the color is consistant throughout the entire package. But, sometimes, like yesterday, there were brown colored sections along with those that are bright red...the visual we all expect. I smelled what I termed to be discolored sections and they smelled fine.
I always check the date on the piece of meat I'm having ground up. In yesterday's case, it was marked 4/12/05 so that's not an issue.
Now, once before I accused a supermarket of having mixed old meat in with new ground beef. Their answer to me was "Sir, when you grind up the meat, the parts not immediately exposed to the air take more time to develop that red color you are used to seeing." They gave me my money back and to this day...well at least until this morning, I thought I was right!
This morning, the remainder of the ground up beef from last night had all turned the red color we all look for. So, perhaps they were right all along? That in order for the entire grind to look the same, air must get at it all on an equal basis?
Thanks for any info from a beef expert.