Full boil hop utilization question - nut brown ale

[tmmeekins]

Hi all...I know this question seems to have been addressed many times but it seems the answer vary. In extract..which is what I currently do....the instructions call for a 2.5 gallon boil. I have now moved to full boil and I'm trying to figure out the hop ratio to compensate...in my reading some made what I thought was a good suggestion...find the all grain kit and see what hop addition it used since all grain was calling for a 5 gallon boil...seemed logical to me so I did check and it called for the same 1 oz 60 min addition in both...another suggestion was to use a calculator where you can change boil size and then adjust the hop amount until you get the same ibu number...sounds logical to me as we'll...so my issue and confusion is that while the extract and all grain both have a 1 oz 60 min hop addition...the calculator shows 9 ibu for extract 2.5 gal but using a 5 gal boil it shows 18 ibu...so I'm not really sure which advice to take or is 9 ibu and 18 ibu really not even noticeable. -- Thanks Mike
Oil it shows 18

 

[Yooper]

Hi all...I know this question seems to have been addressed many times but it seems the answer vary. In extract..which is what I currently do....the instructions call for a 2.5 gallon boil. I have now moved to full boil and I'm trying to figure out the hop ratio to compensate...in my reading some made what I thought was a good suggestion...find the all grain kit and see what hop addition it used since all grain was calling for a 5 gallon boil...seemed logical to me so I did check and it called for the same 1 oz 60 min addition in both...another suggestion was to use a calculator where you can change boil size and then adjust the hop amount until you get the same ibu number...sounds logical to me as we'll...so my issue and confusion is that while the extract and all grain both have a 1 oz 60 min hop addition...the calculator shows 9 ibu for extract 2.5 gal but using a 5 gal boil it shows 18 ibu...so I'm not really sure which advice to take or is 9 ibu and 18 ibu really not even noticeable. -- Thanks Mike
Oil it shows 18

Don't worry about it. It used to be thought that wort gravity (the amount of sugars in solution) affected the IBUs. But that's been disproven since about 2008.

It's true that in a very highly bitter beer that partial boil beers had less bitterness- but that is because of the dilution factor of adding plain water to wort. It really only affects beers where you want more than 50 IBUs or so, though.

For the vast majority of beers, a partial boil hopping is just fine when done as a full boil.

 

[tmmeekins]

Thanks....that makes sense...a beer that calls for a higher bitterness would see the affect. And sorry about the confusing nonsense last line in my post...I have no idea where that came from.