Help with IBU in Beer Smith

I'm adjusting Orfy's Old Speckled Hen recipe for my batch size and hops. I put it in to Beer Smith and it spat out an IBU of 69. I'm expecting bitterness of around IBU 47 based on the original recipe. The IBU total in the ingredients below add up to 48. Anyone know why the IBU is calculated as 69 ?


BeerSmith Recipe Printout - BeerSmith Brewing Software, Recipes, Blog, Wiki and Discussion Forum
Recipe: OSH CLone
Brewer:
Asst Brewer:
Style: English Pale Ale/Strong Bitter
TYPE: Extract
Taste: (50.0)

Recipe Specifications
--------------------------
Batch Size: 23.00 L
Boil Size: 12.00 L
Estimated OG: 1.051 SG
Estimated Color: 10.0 SRM
Estimated IBU: 69.0 IBU
Brewhouse Efficiency: - %
Boil Time: 60 Minutes

Ingredients:
------------
Amount Item Type % or IBU
1.35 kg Light Dry Extract (8.0 SRM) Dry Extract 37.29 %
1.35 kg Light Dry Extract (8.0 SRM) Dry Extract 37.29 %
0.45 kg Lyle's Golden Syrup [Boil for 15 min] Extract 12.43 %
0.37 kg Caramel/Crystal Malt - 60L (60.0 SRM) Grain 10.22 %
67.00 gm Northern Brewer [10.50 %] (60 min) Hops 42.4 IBU
20.00 gm Goldings, East Kent [6.80 %] (15 min) Hops 4.1 IBU
14.00 gm Goldings, East Kent [6.80 %] (5 min) Hops 1.1 IBU
0.10 kg Dememera Sugar (2.0 SRM) Sugar 2.76 %

Go I and check the alpha acid % of each hops. I have found that the percentages are not often the same as whats commonly listed online or the same as what my LHBS sells. My experience has been that the numers in Beersmith are in the upper end of the range for the hops.

Also boil time and boil size can have an effect on the hop utilization and the IBUs.

Other than that, I'm not sure. I'm still a new brewer and have only used Beersmith for a handful of recipes

chode720 said:

Go I and check the alpha acid % of each hops. I have found that the percentages are not often the same as whats commonly listed online or the same as what my LHBS sells. My experience has been that the numers in Beersmith are in the upper end of the range for the hops.

Also boil time and boil size can have an effect on the hop utilization and the IBUs.

Other than that, I'm not sure. I'm still a new brewer and have only used Beersmith for a handful of recipes

Click to expand...

I adjusted the AA% for the hops I have. I expected the total of the IBU values beside each hop addition to equal the total IBU but maybe it's not that simple.

Hmmmm...I can't say I have seen that before, but I also haven't used the program very long. Any chance you can post a screenshot?

chode720 said:

Hmmmm...I can't say I have seen that before, but I also haven't used the program very long. Any chance you can post a screenshot?

Click to expand...

The original post is the exported .txt recipe file from Beersmith.

I'm pretty sure that the individual IBUs should add up to the total. I'm thinking that it might be a bug in Beersmith. I roughly entered the recipe in Recipator and got 52 IBUs (using the Tinseth method). Contact Beersmith and let them know what you're seeing. I'm curious to know what happens.

It might be too early for me to do math properly, but glancing at any of the half dozen or so versions of this recipe on this site, converting them to non-metric measurements, and plugging them into the calculator suggests that your numbers don't look too far off.

Remember that since you're doing a partial boil, your hot wort will have a higher OG, and thus your hops utilization will be off kilter: Realbeer.com Hops Utilization. More bittering hops will be needed for partial boil recipes than with full recipes.

nebben said:

It might be too early for me to do math properly, but glancing at any of the half dozen or so versions of this recipe on this site, converting them to non-metric measurements, and plugging them into the calculator suggests that your numbers don't look too far off.

Remember that since you're doing a partial boil, your hot wort will have a higher OG, and thus your hops utilization will be off kilter: Realbeer.com Hops Utilization. More bittering hops will be needed for partial boil recipes than with full recipes.

Click to expand...

I adjusted the recipe for a late extract addition. What's confusing me is that Beersmith calculates my 60 minute hops addition as 42 IBU, 30 mins as 4 IBU and 5 mins as 1 IBU giving a total of 47 IBU. This is exactly what I was expecting but the IBU of the brew is given as 69 IBU. Hopefully it's just a software bug because I think I've adjusted the recipe correctly.

The changing of the values for AA% for each hop is only one aspect of the necessary change.

Did you also adjust weight amounts and times for each to end up at the desired total?

The program does not know what you are doing; you have to do it.

Henry Hill said:

The changing of the values for AA% for each hop is only one aspect of the necessary change.

Did you also adjust weight amounts and times for each to end up at the desired total?

The program does not know what you are doing; you have to do it.

Click to expand...

Yes I did:

67.00 gm Northern Brewer [10.50 %] (60 min) Hops 42.4 IBU
20.00 gm Goldings, East Kent [6.80 %] (15 min) Hops 4.1 IBU
14.00 gm Goldings, East Kent [6.80 %] (5 min) Hops 1.1 IBU

Total of above: 47.6 IBU.

Estimated IBU: 69.0 IBU ????

I think I've worked it out. Beersmith does not adjust the IBU values of the individual hop additions if you do a late extract addition so the improved hop utilization is not reflected after each hop addition line in the recipe but is reflected in the total expected IBU.

What happens if you turn off the "check box" for late extract addition? That should turn it back down to the correct number.

Adding the extract late does change the IBUs signifcantly.

If you post your Beersmith file here (just click "export as" and use the paper clip icon above to attach it), I can open it and look at it and see what's going on.

YooperBrew said:

What happens if you turn off the "check box" for late extract addition? That should turn it back down to the correct number.

Adding the extract late does change the IBUs signifcantly.

If you post your Beersmith file here (just click "export as" and use the paper clip icon above to attach it), I can open it and look at it and see what's going on.

Click to expand...

Thanks. I'm not allowed to post attachments but I have adjusted as follows: Half the extract and the syrup added with 15 mins to go. I think this is right:

BeerSmith Recipe Printout - BeerSmith Brewing Software, Recipes, Blog, Wiki and Discussion Forum
Recipe: OSH CLone
Brewer:
Asst Brewer:
Style: English Pale Ale/Strong Bitter
TYPE: Extract
Taste: (50.0)

Recipe Specifications
--------------------------
Batch Size: 23.00 L
Boil Size: 11.40 L
Estimated OG: 1.051 SG
Estimated Color: 10.0 SRM
Estimated IBU: 48.2 IBU
Brewhouse Efficiency: - %
Boil Time: 60 Minutes

Ingredients:
------------
Amount Item Type % or IBU
1.35 kg Light Dry Extract (8.0 SRM) Dry Extract 37.40 %
1.34 kg Light Dry Extract (8.0 SRM) Dry Extract 37.12 %
0.45 kg Lyle's Golden Syrup [Boil for 15 min] Extract 12.47 %
0.37 kg Caramel/Crystal Malt - 60L (60.0 SRM) Grain 10.25 %
48.00 gm Northern Brewer [10.50 %] (60 min) Hops 29.1 IBU
14.00 gm Goldings, East Kent [6.80 %] (15 min) Hops 2.7 IBU
10.00 gm Goldings, East Kent [6.80 %] (5 min) Hops 0.8 IBU
0.10 kg Dememera Sugar (2.0 SRM) Sugar 2.77 %
1 Pkgs Nottingham (Danstar #-) Yeast-Ale


Mash Schedule: None
Total Grain Weight: 4.54 kg
----------------------------
Steep grains as desired (30-60 minutes)


Notes:
------

That makes sense. I didn't notice that you had late addition sugars. It's kind of annoying that the individual IBUs aren't adjusted though.

When I evaluated Beersmith a while back, I believe that it didn't count the gravity contribution of steeped grains (crystal in my case). I know they're a small amount of the gravity most of the time, but if you are trying to nail your gravity, you might be confused.

It also depends on which algorithm you have BeerSmith set to use - BeerSmith has three different options for calculating IBUs: Rager, Garetz, and Tinseth.

I ran into a similar (though opposite) problem when I first started using that software - https://www.homebrewtalk.com/f39/beer-smith-overhopping-103930/

I now keep the software set to Rager, though I am not sure that is the ideal solution. In fact, I'm still pretty frustrated by the fact that IBU estimation varies so much depending on which equation is used. At least now, my beers will be consistent and I can adjust the hops in my beers to hit the appropriate bitterness (note I did not say IBUs).

There are also several different IBU formulas in Beersmith.

Try going to Tools->Options->Bitterness and choosing one of the alternate ones.

JLem said:

I now keep the software set to Rager, though I am not sure that is the ideal solution. In fact, I'm still pretty frustrated by the fact that IBU estimation varies so much depending on which equation is used. At least now, my beers will be consistent and I can adjust the hops in my beers to hit the appropriate bitterness (note I did not say IBUs).

Click to expand...

That's the way to go. I've been listening to a lot of Basic Brewing Radio lately and they had an episode on predicting and measuring IBUs. I was astonished to find that some of the different calculation methods vary by as much as 600%. That means that one method could predict 10 IBUs and another could predict 60. Yikes!

Their conclusion was to pick a formula and stick with it. That way, at least you will know how one of your beers compares to another. If you were entering a competition, I suppose you would have to evaluate your IBU prediction method against a beer with a known bitterness.

For those of you who care, the episode was titled "Measuring and Predicting IBUs" from July 5, 2007. Here is the link:
http://media.libsyn.com/media/basicbrewing/bbr07-05-07ibutest.mp3

It's one of my favorites.

It makes sense that the higher IBUs for the final Beersmith calculation are like that. By adding extract and other sugars later on, you have a thinner wort in the beginning, when you are putting in the bulk of your bittering hops. Therefore you'll get better utilization and higher IBU than if you had a high OG wort at 60 minutes. I would think Beersmith is just not updating each hop's IBU contribution when you're looking at the ingredient list.

FWIW, plugging in the revised recipe yields the following IBU estimates:

Rager - 66.6
Tinseth - 51.9
Garetz - 38.4

pick your poison

JLem said:

FWIW, plugging in the revised recipe yields the following IBU estimates:

Rager - 66.6
Tinseth - 51.9
Garetz - 38.4

pick your poison

Click to expand...

My 48 IBU is calculated on Tinseth (seems to be the default on Beersmith). I have the second lot of extract and the golden syrup added 15 mins before the end which might explain why I get slightly less bitterness than you.