Back in October I fermented 5 gallons of fresh pressed cider. I then fermented with English cider yeast. Once fermented out, I racked into another Carboy and filled the headspace with 5 lbs if frozen blueberries. One month later I racked a third time. As of Now, Very blue, and clean. This weekend I want to keg carbonate and later bottle. Has any body ever tried this before? I'm wondering what I should expect for taste as it ages. I found some pure blueberry concentrate and now I wonder if I should add that as a back sweetener