I just added 3 lbs of blueberries to my 5 gallon wheat beer primary. Its been in the primary for a week. In another week I'll transfer to a secondary and scoop out the berries. This is my first fruit beer. I heated up the frozen berries in 160-175 degree water for about 15 minutes to sanitize (I heard that boiling would create pectin, like jam). Then poured them into the primary bucket, stirred, and resealed the lid. Not sure if 3 lbs is a good amount, we'll see.