Pepper notes are a possibility of using coffee. It depends on what type of coffee you used. The most popular would be sumatra or kona for their flavor profiles. Keep tasting every day, as the beans can over power the beer in some situations. If you still dont get the flavor profile you like, brew some coffee and add it in. It would be a good idea to pull a pint of beer from the fermenter, and add the coffee (preferably from a coffee press) a little at a time to find the best ratio of beer to coffee. This technique can also be used with other spices, hops, and mint. Some call this cheating, its up to you.
