I've read that hop utilization changes depending on the gravity of the wort being boiled. If that's correct then it should follow that adding DME to the boil at 60 minutes should result in different IBU than adding at 5 minutes. When I add DME to a recipe in Beersmith it does change the calculated IBU but it doesn't seem to matter when that is added...60 minutes or 5.
Are my assumptions and/or understanding of hops and IBU's just incorrect?
To reproduce what I'm talking about I took one of the sample recipes (NRB's All Amarillo APA) and added 10 lbs of Light Dry Extract at 1 minute left in the boil. This dropped the IBU's to 25.9. I then changed the time to 60 and the IBU's stayed at 25.9.
I'm new to all of this so please be gentle if I'm just being stupid.
Are my assumptions and/or understanding of hops and IBU's just incorrect?
To reproduce what I'm talking about I took one of the sample recipes (NRB's All Amarillo APA) and added 10 lbs of Light Dry Extract at 1 minute left in the boil. This dropped the IBU's to 25.9. I then changed the time to 60 and the IBU's stayed at 25.9.
I'm new to all of this so please be gentle if I'm just being stupid.