Pro Mash/beersmith Different Readings

[Mercs Own]

Just out of interest I put the same information into beersmith and pro mash for a beer I brewed last week. Whilst the srm and the Sg came out the same the ibu's did not??? There was a difference of about 9 ibu's, Pro mash coming in higher.

Strange.

 

[Justin]

There are quite a few different forumlas to calculate IBU's.

Rager, Tinseth, Garetz and generic are the options you can select under Promashs System settings. They are all different and I don't think anyone has come up with a standard. The trick is to pick one and then stick with it, experience from brewing a particular recipe will let you decide if that recipe comes out a bit too bitter or not enough, so next time you might add or subtract a few IBUs, but for most recipes picked up off the net the method of calculating the bitterness is rarely stated. I think for the most part it is close enough though which ever one you use.

I use Rager, but have no real reason as to why.

Cheers.

 

[PeterS]

I adjusted the properties of both Promash and Beersmith to read Rager. Just like Justin, I have no particular reason as to why except to say that they both read the same formular.

:chug:
PeterS....

 

[dreamboat]

I think there is somewhere in Promash where you can choose the formula to be used for calculating the IBU's. I have not ever used Beersmith, but I would suspect that you have the same control with that program also.
If they are both using the same formulae and you still get different values i would be surprised.



dreamboat

 

[Mercs Own]

I have entered the same hop quantities and AA% into both programs and then looked at the given IBU's by each program in each formula, the results

Beersmith: Tinseth - 41.2 Rager - 39.4 Garetz - 26.7

Pro Mash: Tinseth - 37.7 Rager - 38.3 Garetz - 25.6

I also used the same quantaties of wort pre and post boil for each program. There certainly is a significant difference between Garetz and the other two.

 

[Goat]

Not too sure about Beersmith, but Promash has a lot of variables to do with Plug, whole or pellet and storage method etc etc - are all those the same in beersmith?

 

[Aaron]

IBU's is a very inexact science. Just pick a formula and run with it. Most people I speak to use Rager. I also use Rager but for no ther reason than it seems the most popular. It is not worth really worrying about. You just want to be consistent.

Apparently the smallest change the average human can taste is 5 IBU (Acording to DGB) so all of your Tinseth and Rager calculations are really the same anyway.