I brewed this as a 10 gallon recipe a week or so ago, and ended up with 9 gallons (still learning my system). I was planning on bottling the 5 gallon bucket and kegging the 4 gallon bucket and adding coffee to it. I've never added coffee to anything before, so I was wondering how much would be a good amount. One gallon (which would bring me up to five total in the keg) seemed like way too much. Any thoughts? Thanks.