I have found it to be a challenge to estimate the perceived bitterness from FWH and hopstands. More specifically, working in the amount of true bittering addition to come out with a finished product with the bitter backbone I like in my IPAs.
I have experimented with OG in the 1.063-1.068 range. Total IBU estimates in the range of 80-100 but with a large % of that coming from the combo of the FWH/hopstand (hopstands have been at 195* x 30 minutes). My 60 minute IBU have been in the range of only 15-30.
For the next batch I am going to do one of two things. Either increase the bittering addtion to 40-50 and keep all else the same. Or go back to old fashioned methods and get all my IBU from the boil to a total of maybe 75 IBU, then hopstand at lower temp (~165-170) so as not to introduce any additional bitterness variable.
Any thoughts or experiences to share would, as always, be appreciated!