Alright, I’m having a hard time here… I’m trying to calculate how many ounces of hops to use to reach a KNOWN IBU. However, all the equations I come across are the other way around, i.e. you have a known amount of hops and you’re looking to determine the IBUs. I know it’s just a simple re-arranging of the equation, but my math skills have gone out the window, apparently, and I can’t figure it out.

For my equation, I’m looking to determine how many ounces of Chinook to use (AA 11.4%) at 60 minutes (start of the boil) to reach an IBU of 40. Hop utilization at 60 minutes for an OG of 1.050 is 0.231.

Help/thoughts?

Avery