I was am brewing a recipe from a rather famous home brewers book and when I entered into my spreadsheet had a wildly different IBU result than the recipe called out. My next step was to enter it into the Brewer’s Friend IBU Calculator an the results were of course different again. Book recipe 1.055 OG 7 gallon boil 6 gallons finished wort 1.8 ounces of 5% AA hops for 60 minutes IBU 36 Brewer’s Friend IBU 29.25 Mine IBU 25.67 The difference between my calculations and Brewer’s Friend come down to utilization my U = .23 and Brewer’s Friend U = .26. How would you get 36 IBU out of those hops? A U = .32. Thanks for any insights.