I would try frozen ripe bananas in the secondary. I assume you will get a pretty significant fermentation out of them, lots of sugar. I assume moderate hops, but enough to balance the sweetness, probably a floral variety? I had a sour banana beer years ago that was really pretty nice. Some toasted, biscuit character would balance the bananas.
I have not had the beer you are sourcing. What is its strength and character?




