Beersmith Boil Volume - IBU change

[Iowabeerguy]

When changing the boil size from 5 gallons to my 3 gallon partial mash brew pot it dramatically changes the IBU's - I'm relatively new with building recipes, do I really need to use considerably more hops when doing a smaller boil or do I have a setting out of whack in Beersmith?

 

[FlyingHorse]

Hard to know if you have a problem without more details, but assuming all you changed was the size of the boil, then yes:

Smaller boil = higher gravity = lower utilization = more hops

 

[Iowabeerguy]

That makes sense - thanks