What is an IBU? It’s a simple question — wait until you hear the answer.
Written by John Palmer
Issue: March-April 2008
Calculating the impact a fruit addition will have on a beer’s ABV is tricky — so much so that even commercial brewers have gotten in trouble for miscalculating their influence on gravity. We take a closer look at the math required to get it right.
IBU calculators most often used by brewers were developed prior to the popularity of adding massive hop additions after the boil. As brewing techniques evolve, the way we measure IBUs should too. A new model, dubbed SMPH, accounts for factors that have previously been overlooked, including separating isomerized alpha acids from auxiliary bittering compounds.