title_body: How to tell if coffee beans are burnt?
upvoted_answer: Char - smell and taste. Excessive oil coating the surface of the beans. The extracted coffee will have a flat taste. Hard to describe, but the taste will be predominately "charred" and nothing else.
  
  Cracking a bean open may help, I don't think it should be black through and through, but I don't have any experience with that.
  
  Can you actually return beans?