IBUs and Late LME Additions

[prpromin]

Messing around with Beer Calculus and inputting a recipe that I made a few days ago, I noticed that when I designated my LME as a late addition, my IBUs went from 57 to 102. My question is, how does that work? I don't think it's a problem, but I want to better understand what's going on.

Note that 3lbs of DME was added at the beginning of the boil (and grains were steeped prior to that). Is there more information I need to give for an explanation?

Thanks in advance.

 

[TexasAggie]

It is based around the idea that hop utilization is affected by the amount of sugar in the boil. I just finished a keg of Centennial Blonde that used a 30 min DME addition. I wanted to test the theory and get a malt forward blonde. The result was nothing drastic regarding either the malt flavor or the hops (no noticeable increase in IBUs). Previous versions of Beersmith did not show higher IBUs with late malt additions but I think the idea is more generally accepted as true now.

 

[prpromin]

Thanks. I figured it was something like that - I was just surprised to see such a huge jump from making the LME a late addition.