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IBU problem


Jul 19, 2014
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hops are 1g tettnang (4.50%) at 60, 1g Tettnange (4.50%) at 15min, and 1gram of Spalter select (3.9% AA) at 2 minutes. In the recipe it shows 16.3 IBU and using the Hop Bitterness tool it shows 26.8 IBUs. I suspect i made an error in the equpment profile but not sure how to fix this. I am showing my a screenshot of the equpment profle. I have 240v, 30 amp electric HERMS system, 10 gallon pots for a 5 gallon brew.


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It is hard to tell from the equipment profile shots directly, but the boil volume and into-fermenter volumes are most important for getting things right.

Keep in mind also that the recipe calculator in general is more accurate as it takes into account things like boil gravity, small volume losses and of course whirlpool hops.

Here's the equipment super post which might help you dial in your particular set of equipment:

Also if you are using commercial equipment, many of the equipment profiles are available as add-ons under File->Addons.

not sure if this helps. Made my electric pots, etc. from what I used to use on gas


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We are intrigued by your problem. This is what makes home brewing fun! First thing noted was your Mashing in a cooler with dead space accounted for in equipment profile. .5 gallons seems just a tad high possibly, but a 1 gallon loss in boil kettle does seem excessive based on our experience. Another item of concern would be Water Volume correctly entered in recipe and of course grain bill totals. Looking at the BS bitterness tool make sure Batch and boil volumes are the same in recipe. Double check Alpha entries, times, hop amounts and BOIL SG all equal on tool and recipe.

I took one simple recipe and checked by recipe IBUs with Bitterness Tool IBU calculations. Noted multiple formula's to choose from. I saw a discrepancy, as well, at the low end of Boil times (10 minute area). Off by several IBUs. Odd that the upper value was within nearly 1 IBU. Still kind of close for I would not expect the same values. Please keep in mind no software is perfect. Kind of like us the creators of software. We are all imperfect. As an example, I am addressing my smart phone each day in a a foul matter for it does not always do what I command it to do and it does a lot of other things I wish it would not do on it's own.

The only other mystery (we think?) a foot might be BS software updating correctly after edits. I have seen multiple times where I went in and out of a BS recipe and found different values. Always wondered if it is a my (the father) personal old age thing or is reality actually in front of my face as I see it. I thought I saw.......? GOOD Luck solving your mystery, would like to hear feedback on your resolution.