# Homebrewers Association | AHA Forum

## General Category => General Homebrew Discussion => Topic started by: rayallen on March 09, 2011, 04:23:03 PM

Title: AAU and IBU
Post by: rayallen on March 09, 2011, 04:23:03 PM
Ive been reading my book How To Brew by John J Palmer.

I have to say there are a lot of Math equations in brewing. I understand how to come up with my AAU but the IBU seems to be far more complex.

I was a ok math student but its definately not my favorite subject.

Can someone break down the IBU in laymen's terms.

I know with me being a newbie its not super important for me to know this but when I start creating my own recipes its good to know.
Title: Re: AAU and IBU
Post by: denny on March 09, 2011, 04:42:01 PM
Ray, what is it that you're looking for?  A way to calculate what the IBU of your beer will be?
Title: Re: AAU and IBU
Post by: rayallen on March 09, 2011, 04:51:58 PM
exactly

according to his book there is more than one way to to calculate IBUs, he goes on to say different hobbiest use different methods.

What is the most used general IBU calculator or equation preferred.

Id like to have the simplest way possible. If someone asks what is the IBU of your bere, I can answer them.
Title: Re: AAU and IBU
Post by: denny on March 09, 2011, 04:57:59 PM
Well, I use Promash to do all the technical stuff like that for me.  There are 3 generally accepted formulas for figuring IBUs.  Rager, Tinseth, and Garetz.  Generally, Rager is considered the one to use for partial boils and Tinseth for full boils.  I use Tinserth and when I've had beers analyzed for IBUs, the results come very close to the prediction Promash made.
Title: Re: AAU and IBU
Post by: rayallen on March 09, 2011, 05:15:22 PM
WOW, didnt realize there were programs.software I could use do solve these equations for me.

I see that I could use Promash or Beersmith. The one thing I just noticed at Promash's site is that they do not have a link for Windows 7 which is what Im running.

Thanks Denny
Title: Re: AAU and IBU
Post by: tschmidlin on March 09, 2011, 05:24:46 PM
Both work with Win 7, you should get a trial version of each and see which one you like the best.  There are others, but these two I am most familiar with.  Both work fine, it's personal preference.
Title: Re: AAU and IBU
Post by: dcbc on March 09, 2011, 05:39:35 PM
Looks like there is a big update for Beersmith coming soon.  Brad has been working on it for a couple of years now.  Multiplatform support among other upgrades.  I have always been impressed with the level of support offered for this software.  He is very active on his forum and seems very eager to help users and improve the product.
Title: Re: AAU and IBU
Post by: rayallen on March 09, 2011, 05:50:29 PM
Thanks guys from some of the reviews I found its all personal preference.

It seems as though from what I read that promash doesnt update their software as often.

I will do a trial on both and see which I prefer.
Title: Re: AAU and IBU
Post by: denny on March 09, 2011, 05:53:46 PM
It seems as though from what I read that promash doesnt update their software as often

Promash hasn't been updated for a long time, but it doesn't need to be AFAIAC.  It does everything that needs to be done on a clear, accurate fashion.  That said, it does come down to a matter of preference.
Title: Re: AAU and IBU
Post by: hopfenundmalz on March 09, 2011, 09:28:38 PM
I was lucky to had some beers measured, and Tinseth come out closest for me, full boils in a converted keg.

Don't get too hung up on it.  Find  a commercial beer that has a published, believable IBU, like Sierra Nevada Pale Ale, try and brew a similar beer and see how they compare.

Your resolution on IBUs is about 4 or 5 before you can say one is more bitter than the other.  The routines require inputs on AA which goes down with time.  Process has its own influence.  The strain of yeast will have and impact,  as the bitter resins stick to the yeast membranes.

As an old tech used to say in the Engineering Lab - "Measure it with a micrometer, mark it with chalk, cut it with an axe".  I miss that guy.
Title: Re: AAU and IBU
Post by: rayallen on March 09, 2011, 10:27:28 PM
Personally im not into super hobby beers like IPAs, im more of a Wit, wheat and Ale guy my self. My wife loves IPAs though so I will brew them from time to time.
Title: Re: AAU and IBU
Post by: a10t2 on March 10, 2011, 12:02:48 AM
Personally im not into super hobby beers like IPAs, im more of a Wit, wheat and Ale guy my self. My wife loves IPAs though so I will brew them from time to time.

Well in that case you're golden. The styles you like are probably going to be 15-30 IBU, where a difference of even 20% won't be perceptible, and if your wife is a hophead, she won't care if that IPA comes out at 60 IBU or 80. It's in between those ranges that you have to worry.