Adding coffee to gravy

So I found a recipe for what is an amazing brown gravy, well not a completely written out recipe but one scratched down by my Grandma in her old cook book. Grandmas brown gravy was always the best and she used to say she would never tell why, but I found it. It was coffee. Which makes sense for the rich flavor. Now she used to use left over brewed coffee but I use Javvy coffee concentrate. Do you think it would translate the same taste if I mixed it like a regular strong cup?