Author Topic: IBU discrepancy  (Read 6076 times)

Offline AnthonyB

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IBU discrepancy
« on: December 29, 2011, 02:49:46 PM »
The IBUs listed on the grid (33.3 + 10.1 + 9.2 + 3.9 + 2.5 + 5.4 + 6.0 + 5.5 = 75.9) don't sum up to the IBUs listed under bitterness (105.4) for my recipe.  Any idea what is going on?  I do have a late Extract addition.

Type: Extract Date: 12/17/2011
Batch Size (fermenter): 5.00 gal Brewer: Anthony B
Boil Size: 4.00 gal Asst Brewer:
Boil Time: 60 min Equipment: My Equipment
End of Boil Volume 3.64 gal Brewhouse Efficiency: 75.00 %
Final Bottling Volume: 5.00 gal Est Mash Efficiency 0.0 %
Fermentation: My Aging Profile Taste Rating(out of 50): 35.0
Taste Notes:
Ingredients
Ingredients

Amt Name Type # %/IBU
2 lbs Caramel/Crystal Malt - 40L (40.0 SRM) Grain 1 18.2 %
8.0 oz Special Roast (50.0 SRM) Grain 2 4.5 %
4 lbs 4.0 oz Extra Light Dry Extract (3.0 SRM) Dry Extract3 38.6 %
1.00 oz Columbus (Tomahawk) [13.30 %] - Boil 60.0 min Hop 4 33.3 IBUs
0.50 oz Columbus (Tomahawk) [13.30 %] - Boil 20.0 min Hop 5 10.1 IBUs
0.50 oz Simcoe [12.20 %] - Boil 20.0 min Hop 6 9.2 IBUs
4 lbs 4.0 oz Extra Light Dry Extract [Boil for 15 min](3.0 SRM) Dry Extract7 38.6 %
0.50 oz Amarillo Gold [8.50 %] - Boil 10.0 min Hop 8 3.9 IBUs
0.50 oz Cascade [5.50 %] - Boil 10.0 min Hop 9 2.5 IBUs
0.50 oz Chinook [11.80 %] - Boil 10.0 min Hop 10 5.4 IBUs
0.50 oz Columbus (Tomahawk) [13.30 %] - Boil 10.0 min Hop 11 6.0 IBUs
0.50 oz Simcoe [12.20 %] - Boil 10.0 min Hop 12 5.5 IBUs
2.0 pkg Dry Ale Yeast (Fermentis #Safale US-05) [50.00 ml] Yeast 130.50
oz Amarillo Gold [6.90 %] - Dry Hop 7.0 Days Hop 14 0.0 IBUs
0.50 oz Cascade [5.50 %] - Dry Hop 7.0 Days Hop 15 0.0 IBUs
0.50 oz Chinook [11.80 %] - Dry Hop 7.0 Days Hop 16 0.0 IBUs
0.50 oz Columbus (Tomahawk) [13.30 %] - Dry Hop 7.0
Days Hop 17 0.0 IBUs
0.50 oz Simcoe [12.20 %] - Dry Hop 7.0 Days Hop 18 0.0 IBUs

Beer Profile
Est Original Gravity: 1.077 SG Measured Original Gravity: 1.086 SG
Est Final Gravity: 1.018 SG Measured Final Gravity: 1.019 SG
Estimated Alcohol by Vol: 7.8 % Actual Alcohol by Vol: 8.9 %
Bitterness: 105.4 IBUs Calories: 297.5 kcal/12oz

Thanks,
Anthony

Offline AnthonyB

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Re: IBU discrepancy
« Reply #1 on: December 30, 2011, 04:19:35 PM »
So if I change the boil time of my late extract add, the individual line item IBU numbers do not change but the Bitterness (IBUs) change.  It looks like adjustments for late extract adds are not reflected on the individual ingredient lines.

Is this by design or just something that was overlooked?

Thanks,

Anthony

Offline Hoppy Brewer

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Re: IBU discrepancy
« Reply #2 on: January 11, 2012, 09:15:12 PM »
BeerSmith 2.0 (2.0.57)
I also have questions about the difference in IBU's displayed in the recipe 'Design' view and the 'Hop Bitterness' tool. After Brewing a recipe according to the IBU estimates in the 'Design View', I later discovered the 'Hop Bitterness' tool (shame on  me for not seeing it sooner?) and entered the same values as in the 'Design' view. See the attachments. Notice the differences in the IBU values, yet all other values are the same, most importantly, Alpha Acid values.
The beer actually is much more bitter than 50.9 IBUs. You would think that the two would be at least somewhat close to each other, but the 'Hop Bitterness' tool shows a value of about 15 points higher. I think the 'Hop Bitterness' tool is more accurate and  the IBU values in the 'Design' view are incorrect (a bug?). How do we properly design a recipe in the 'Design' view if the IBU calculations are wrong?
« Last Edit: January 11, 2012, 09:21:39 PM by Hoppy Brewer »

Offline glienhard

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Re: IBU discrepancy
« Reply #3 on: January 12, 2012, 09:28:46 AM »
Hey Anthony,

Could you attach a copy of your recipe so I can plug it into my computer and take a look at it?

Cheers!


So if I change the boil time of my late extract add, the individual line item IBU numbers do not change but the Bitterness (IBUs) change.  It looks like adjustments for late extract adds are not reflected on the individual ingredient lines.

Is this by design or just something that was overlooked?

Thanks,

Anthony
« Last Edit: January 13, 2012, 08:11:38 PM by glienhard »

Offline glienhard

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Re: IBU discrepancy
« Reply #4 on: January 12, 2012, 03:25:11 PM »
The couple things that come to mind, just off the top of my head, are hop form and boil volume.  The form of the hops in your recipe and the calculator might be different.  For instance, BS defaults all hops to pellet form.  Pellet hops will have a higher utilization and produce higher numbers.  Also, the boil volume will make a difference.  If you boil at a concentrated volume, it will affect the hop utilization.


BeerSmith 2.0 (2.0.57)
I also have questions about the difference in IBU's displayed in the recipe 'Design' view and the 'Hop Bitterness' tool. After Brewing a recipe according to the IBU estimates in the 'Design View', I later discovered the 'Hop Bitterness' tool (shame on  me for not seeing it sooner?) and entered the same values as in the 'Design' view. See the attachments. Notice the differences in the IBU values, yet all other values are the same, most importantly, Alpha Acid values.
The beer actually is much more bitter than 50.9 IBUs. You would think that the two would be at least somewhat close to each other, but the 'Hop Bitterness' tool shows a value of about 15 points higher. I think the 'Hop Bitterness' tool is more accurate and  the IBU values in the 'Design' view are incorrect (a bug?). How do we properly design a recipe in the 'Design' view if the IBU calculations are wrong?

Offline Hoppy Brewer

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Re: IBU discrepancy
« Reply #5 on: January 12, 2012, 04:51:27 PM »
Boil volume and hop form (pellet) are the same in both. Next?

Offline DaveK

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Re: IBU discrepancy
« Reply #6 on: January 13, 2012, 03:43:06 PM »
I'm having a similar problem. I am using version 1.4 build 037. I'm not using the bitterness tool though. Sometimes, but not always, when I create a recipe, the IBUs listed in the ingredients section do not match the number in the beer profile section below that. I know that changes in volumes, boil times, late extract additions, etc change the IBUs; and I have seen that. But why would these 2 numbers in the same recipe EVER be different from one another? In the latest case I have only one hop addition - 2 oz of pellet hops at 60 minutes. After clicking new recipe, I selected the extract and the hops. I did nothing else. I made no changes. The numbers were different right from the start.

As I said, it doesn't always happen. In an effort to troubleshoot this issue I selected a batch where the 2 numbers matched. Mind you I am using the identical extract and hop ingredients. I then set about changing every variable under the sun to try and MAKE the 2 numbers different from one another. Each change that I made changed the numbers in the way that I would expect to see, but the numbers were always the same.

What am I missing?

Offline BeerSmith

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Re: IBU discrepancy
« Reply #7 on: January 13, 2012, 05:48:07 PM »
Hi,
  The recipe design view includes losses (i.e. it bases the hop calculation on the batch volume plus the losses into trub/chiller).  This is consistent with the conditions the various hop estimating formulas were developed under - in fact I've discussed this point with Glenn Tinseth.    The issue is that the formulas are based on "post boil" volumes - so some bitterness is thrown away with the trub/chiller losses.

  The net result is the recipe design view is using a slightly higher volume than the hop bitterness tool for a matching batch size, resulting in a bit lower values.

  The hop tool obviously does not factor in trub/chiller losses.

  I've run some tests here and you can get both to match up with the proper equipment settings.  Internally they do use the same formulas - except for the batch size issue.

Cheers!
Brad
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Offline AnthonyB

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Re: IBU discrepancy
« Reply #8 on: January 27, 2012, 04:47:24 AM »
Hey Anthony,

Could you attach a copy of your recipe so I can plug it into my computer and take a look at it?

Cheers!



I'm fairly sure that all the pertinent recipe information was in my first post.  Wasn't it?

Type: Extract Date: 12/17/2011
Batch Size (fermenter): 5.00 gal Brewer: Anthony B
Boil Size: 4.00 gal Asst Brewer:
Boil Time: 60 min Equipment: My Equipment
End of Boil Volume 3.64 gal Brewhouse Efficiency: 75.00 %
Final Bottling Volume: 5.00 gal Est Mash Efficiency 0.0 %
Fermentation: My Aging Profile Taste Rating(out of 50): 35.0
Taste Notes:
Ingredients
Ingredients

Amt Name Type # %/IBU
2 lbs Caramel/Crystal Malt - 40L (40.0 SRM) Grain 1 18.2 %
8.0 oz Special Roast (50.0 SRM) Grain 2 4.5 %
4 lbs 4.0 oz Extra Light Dry Extract (3.0 SRM) Dry Extract3 38.6 %
1.00 oz Columbus (Tomahawk) [13.30 %] - Boil 60.0 min Hop 4 33.3 IBUs
0.50 oz Columbus (Tomahawk) [13.30 %] - Boil 20.0 min Hop 5 10.1 IBUs
0.50 oz Simcoe [12.20 %] - Boil 20.0 min Hop 6 9.2 IBUs
4 lbs 4.0 oz Extra Light Dry Extract [Boil for 15 min](3.0 SRM) Dry Extract7 38.6 %
0.50 oz Amarillo Gold [8.50 %] - Boil 10.0 min Hop 8 3.9 IBUs
0.50 oz Cascade [5.50 %] - Boil 10.0 min Hop 9 2.5 IBUs
0.50 oz Chinook [11.80 %] - Boil 10.0 min Hop 10 5.4 IBUs
0.50 oz Columbus (Tomahawk) [13.30 %] - Boil 10.0 min Hop 11 6.0 IBUs
0.50 oz Simcoe [12.20 %] - Boil 10.0 min Hop 12 5.5 IBUs
2.0 pkg Dry Ale Yeast (Fermentis #Safale US-05) [50.00 ml] Yeast 130.50
oz Amarillo Gold [6.90 %] - Dry Hop 7.0 Days Hop 14 0.0 IBUs
0.50 oz Cascade [5.50 %] - Dry Hop 7.0 Days Hop 15 0.0 IBUs
0.50 oz Chinook [11.80 %] - Dry Hop 7.0 Days Hop 16 0.0 IBUs
0.50 oz Columbus (Tomahawk) [13.30 %] - Dry Hop 7.0
Days Hop 17 0.0 IBUs
0.50 oz Simcoe [12.20 %] - Dry Hop 7.0 Days Hop 18 0.0 IBUs

Beer Profile
Est Original Gravity: 1.077 SG Measured Original Gravity: 1.086 SG
Est Final Gravity: 1.018 SG Measured Final Gravity: 1.019 SG
Estimated Alcohol by Vol: 7.8 % Actual Alcohol by Vol: 8.9 %
Bitterness: 105.4 IBUs Calories: 297.5 kcal/12oz


Offline glienhard

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Re: IBU discrepancy
« Reply #9 on: January 27, 2012, 07:57:13 PM »
My apologies, I had meant to ask for the recipe file. That way i could import it into my computer, rather than type it all in manually.  No worries.  I think that Brad answered your question though.  " The net result is the recipe design view is using a slightly higher volume than the hop bitterness tool for a matching batch size, resulting in a bit lower values."