Castle Eden Contradiction

[Kingfisher]

Whilst putting a few of Marc Ollosson's recipes onto Promash I've noticed a difference in the MO bittering units and those given by PM. for instance Castle Eden Bitter MO gives 23 bittering units and PM 44.3 total IBUs.

The recipe has 835g of inverted sugar added. Will this affect the IBUs and make MO's correct

 

[Vossy1]

On page 26 (in my MO book) Marc states that the utilization rate for the hops is set at 20%, which is very low.
Running them through this calculator at 20% I get 26 IBU for 35g of target at 8.7%AA

If you change the utilzation figure to 26% you'll get 34 IBU
I've just double checked it through Beersmith using Tinseth and it confirms 34.2IBU.

44.3 IBU seems a little high on PM :hmm:

 

[Kingfisher]

Just changed the settings from Rager to Tinseth and they drop slightly on the main brew calculation page. Using the PM hop calculator for Target I get 32.92 on 10%aa but the main brew formula for 30g Target is 39.8 IBU.