Patsy,
   I do use coffee as a seasoning. I'm not talking about dry grounds, but already brewed coffee. I let it cool first because adding boiling hot coffee would start the cooking process early. It doesn't really add bitterness, but more of a musky savoriness. I got the idea from an article I read years ago about the Menches Brothers from nearby
Akron, Ohio who supposedly invented the hamburger(there are competing claims). As the story goes they were selling pork sandwiches at a county fair near Hamburg, NY and the fairground butcher ran out of pork and offered to grind some beef for them. One of the ingredients they used to flavor it with was coffee. Their descendants also claim they invented the ice cream cone at another fair when they ran out of paper bowls and rolled waffles into a cone shape. Personally, I think they just invented stories.