I thought my last Dunkel was a little weak in hops bitterness, so I put some Crystal hops in a SS hop infuser 300 mesh (including the lid) and sat it in the 3 gallon keg. Tried the beer in 6 hours and seemed VERY strong with hops, so I pulled them out. After it sat in the keg a couple of days, the excessive hopiness diminished and is about right now.