Calculating IBU's for a brew

[banger]

Hi all,

If I want to calculate the level of IBU's in a particular brew, do I use the volume of the boil in which the hops are added, or the total volume of the brew (ie. after cold water is added)? I suspect it's the latter, but can anyone set me straight?

Cheers,

SR

[earle]

Use the final volume of the brew to calculate the IBU then do smaller boil of the same gravity to get similar utilisation. So if your boil is 1/4 of your final volume add 1/4 of your fermentables to it or for those who like formulae

amount of fermentables in boil = boil volume/final volume x total fermentables

[rwh]

http://www.rooftopbrew.net/ibu.php

[Boonie]

Or get Beersmith.

I just purchased it recently and it is great.

You can do a Trial version for about a month.

When you get it, make sure you have time available to test it properly.....

It works a treat and I find I am using it for every brew now...mind you, that's not been many lately.......just kegged a brew I made weeks ago.

Cheers

Boonie

[warra48]

+1 for Beersmith.

It works really well, and allows you to develop your recipes on the go, so to speak. As you build your recipe, it will adjust the predicted IBUs and OG etc, so you can adjust it till you get the result you are looking for.
Once you go AG, you will definitely need a program like Beersmith, or Promash or the like.