I haven't ever tried coffee in my pot roast. I just sprinkle mine roast with pepper, grandular beef boullion and flour. Brown it on all sides in olive oil. Remove roast from the pan and place it in the crock pot with about 2 cups of water. Add my carrots (sometimes onion and celey).
Then I take the pan I brown the roast in and add 2 more cups water, stir it , to pick up all pan drippings, add more granular beef boullion then pour this in the crock pot. If I need to, I add more water to cover the roast. Cook it all day long on high. The gravy is not thick, but can be thicken if anyone wants cream gravy.