Ok guy's I really have to respond to this. In over 35 years as a butcher, I have heard this thing about ground beef red on the outside and brown on the inside. I have even had some customers tell me that we take old ground beef and wrap fresh ground beef around it. It takes all I can do to not laugh out loud. Where do they get that stuff from LOL. Do people really think we have time to do that? Grinding old meat mixed with fresh meat was done many years ago, but I dont know any place that does this. The reason ground beef is red on the outside is because oxygen can still get to the surface creating a "bloom". Does not take long for that same fresh ground beef when packaged to turn a brown color on the inside. This is NORMAL. This is because all oxygen is cut off. This is also why you see in a meat service case, butchers put paper between layers of steaks for example. If steaks were layered on top of each other, the steaks underneath would turn a dark color and not appetizing.
Great care is taken in grinding meats these day's. The ground beef that is freshly ground right now and wrapped for the counter usually has a two day code date. Doesn't mean it will be bad on the third day, just a way for the butcher to know that on the second day, he will reduce the price. That is when I jump in and buy it. Up here if a grocery store sold out of date ground beef [on purpose] or mixed old beef with fresh to grind, they would get fined and there is not one store that I know of that want's that kind of publicity.
Watch your code date's on any products for that matter. Commercial ground beef is all processed under federal inspection and all ground beef must be ground fresh. The pork in question in this thread from what I read was bad. It should not have any oder as stated. Once meat is ground bacteria can grow faster than meat left whole like a roast for example. So when you buy ground beef, pork, or chicken you should use it or freeze it, even if you grind it at home on your own. Sure grinding at home can save you some money at times, and can be better for you can grind the cuts of your choice. However also don't be afraid to buy ground meats at your favorite store. Reinhard