I highly doubt you'll taste much of the kiwi in a tripel. It's a VERY subtle flavor. When I make my Kiwi Wit, I use about 5lbs of Kiwi (peeled and cubed) to give me a nice tart flavor, but it's not what you'd expect. If I were going to try anything heavier than a Wit, I'd at least double the fruit.
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Another HERMS rig...