partial boil hop utilization

[Col_klink]

hello all,
Ive been reading a lot about the affects of doing a partial boil on hop utilization and thd overall IBU of your beer. I am hoping someone could check my understanding of this.

so if I have a 3 gallon boil that is calculated to be say 50 IBUs. Then I top that off with 2 gallons of water in the fermentor. My beer would end up at 30 IBUs? Does that sound right?

Also, when using brewer's friend IBU calculator. I put 3 gallons in the 'boil size' field and 5 gallons in the 'batch size' field. Does the total IBUs the calculator gives me taking into account that I am topping off with 2 gallons of water? Or do I need to adjust that number myself?

Any input would be much appreciated.

THANKS,
Klink

 

[brew_ny]

Also, when using brewer's friend IBU calculator. I put 3 gallons in the 'boil size' field and 5 gallons in the 'batch size' field. Does the total IBUs the calculator gives me taking into account that I am topping off with 2 gallons of water?

yes it does if you change the boil size the number change that is the whole idea behind using software

all the best with your brewing

S_M

 

[unionrdr]

That's my current understanding of BS2 as well. Although it is my concidered opinion that BS2 goes a bit heavy on IBU's,regardless of when they go into the boil.

 

[Col_klink]

thanks guys!