Hi BF Forum! Im debating with my friend about the IBU, specially Tinseth formula, from Brewers Friend. There's a lot of variation, i know, but Brewer's Friend seems to be the higher IBU number comparing to most sources. Since the base formula is simple, AAU basically equal, so the "problem" could be the Utilization ("U") number. Maybe too high. Actually, it's not a problem itself, since IBU could be only estimated. But it's strange, because BF gave the higher value in this parameter, comparing with other calcs. Cheers!