Previously, the default IBU calculation for Beer Calculus was based on an average of a few popular formulas. It did four calculations (Garetz, Rager, Tinseth, and the legacy Hopville calc) and averaged them together. I chose to blend a few conflicting numbers together instead of committing to a single one by default. That neutral position tended to cause some confusion among both types of brewers: those who cared which formula was in use, but didn’t know you could change it, and those who didn’t care at all. Plus, the only indication that a formula selection was being made was a subtle message “avg” near the IBU result – pretty vague about what was happening behind the scenes. Recipes now default to the Tinseth formula. Hopefully this will satisfy those who prefer this formula, and also clarify the default calculation to folks who don’t really care.