Glad you asked...
If you have spoiled ground beef you will know. The smell alone will tell you. Also if the color isnt pink you probaly have bad ground beef. Check the date on the meat.
Then again, this answer might help you...
To tell if ground beef is spoiled look at the color. If brown or greenish all the way through it is starting to go bad. Ground beef will also have a sour smell if it is going bad.

