Have used kaffir lime leaves in a coopers lager kit- cant remember the grain and hop additions, but was similar to a barefoot at finishing-although from memory a tad bitterer.I always meant to try it again but never got to it. I do know I smashed 6 leaves with the blunt side of a knife and threw them in after 5 days though- I've gotta start taking better notes!AQuestion to those wanting to add lime. have you thought about adding Kaffir Lime Leaves? you could make a little tea and with the leaves to help extract some flavour from the leaves, it might avoid extracting any bitterness from the pith of the fruits. Just a thought.
Cheers Jan