Full Boil Conversion

[jb1677]

I wanted to adjust a recipe from a partial boil to full boil. I have read many many many many threads with different information and others that simply said use a calculator to see the difference.

I tried both Beersmith and TastyBrew.com but got grastically different results.

At a 5 gallon boil I get the same IBU with both calculators, when I lower the boil size to 2.5 gal I see IBU's drop in beersmith (expected I think since I get less hop utilization) but with tastybrew.com's calculator I get an INCREASE in IBU's suggesting better hop utilization.

What gives, who is right?

 

[tonyc318]

Bring a third in to the equation and try hop calculus on hopville.com it show me that the partial boil (with same mount of extract for boil duration) decreases hop utilization.

 

[jb1677]

I missed the ability to adjust boil volume there, will have to take a look again - so you. basically get the the same results as beer smith

 

[RiffMagnum]

I've also heard many people who don't adjust the recipes at all. That's what i've been doing and my beers turn out great. Although i'll admit, i'm not a hophead so getting the hop utilization down perfect isn't really a big deal for me. I guess if you were trying to make a perfect clone of a commercial beer it might be more of an issue.

 

[Brewnoob1]

I went to full boils from 2 gallon and never adjusted my recipe. You may get better hop utilization so therefore need less, but I don't mind a little kick either....so I left it alone. All my beers have turned out awesome so far without messing with a thing. I use BeerSmith and if I'm still in the green and reasonable for the brew, I call it good. That's just me though...

 

[jb1677]

Using beersmith and only changing the pre boil volume moves my IBU from "in the green" with a 2.5 gal boil to "in the red" with high IBU with a 5 gal boil which is what had be worried.

The tastybrew calculator shows IBU dropping based on pre boil volume.

I am completely missing where I can adjust water volumes in hopville's calculator.

 

[Brewnoob1]

Hmm, I noticed a difference in IBUs but never that drastically. It definitely raised moving to full boils, but never enough to deter me away from changing the recipe. Good luck though!

 

[tonyc318]

Using beersmith and only changing the pre boil volume moves my IBU from "in the green" with a 2.5 gal boil to "in the red" with high IBU with a 5 gal boil which is what had be worried.

The tastybrew calculator shows IBU dropping based on pre boil volume.

I am completely missing where I can adjust water volumes in hopville's calculator.

The is a little spot under the hop schedule where you can edit the average boil volume. It's not super obvious.

 

[tonyc318]

Also, in the calculators, play around with the timing of your additions. See what that will do for you too. It's interesting.

 

[jb1677]

The is a little spot under the hop schedule where you can edit the average boil volume. It's not super obvious.

Bingo! thanks. Hopville's numbers now basically match beersmith's - so I guess tastybrew is wrong..... weird

 

[tonyc318]

Bingo! thanks. Hopville's numbers now basically match beersmith's - so I guess tastybrew is wrong..... weird

I have not played with tastybrew or beersmith, but everything I've heard or read has mentioned boil gravity effects hop utilization. So, if I put 6lbs of LME into 2.5 gallons of water, the concentration is higher and the boil gravity is higher. If I add the same amount of LME to 6 gallons of water, the sugars are less concentrated and the boil gravity is lower. Or like wise, if I add only half of that LME to 2.5 gallons then add the rest at flame out.
You have probably heard or read about that too. I use the hopville.com tool because aim mostly on an iPad and it's free.