Hop additions

[MARMITE]

I am planning some comparison brews to assess the IBU's required to attain a certain level of bitterness.The general view seems to be that a 90 min boil acheives maximum extraction whereas soak hops only add flavour and aroma.This is not my experence. Eg
1 My BPA entered at Sutton received the comment " need more hops"
2 An identical brew except I took a leaf out of Sara's book and added 56 grams of soak hops has been commented on as follows my a couple of mates
1 A bit too bitter for me
2 That's got a nice bite
It seems that the post boil hops have added considerable bitterness to the second brew I wonder if anyone else agrees.Is it reasonable to assume for instance that say late hops extract 50% bitterness and post boil hops extract 25% or has anyone got any better ideas?

[Invalid Stout]

You're not comparing like with like. Maybe the judge likes hops more than your mate does. In which case it would be possible for the same brew to "need more hops" for one person and at the same time be "too bitter" for the other.

[MARMITE]

Thanks for the replies
Chris I think you are right Perhaps I'll assume the % bitterness that is extracted at each stage of the brewing process and review this in the light of experience.
Invalid stout It isn't a matter of different perceptions of bitterness. There is no doubt that the second brew is a lot more bitter.I should know ,I've tried them both many times.