Author Topic: Whirlpool Bitterness Discrepancy!!!  (Read 3651 times)

Offline dentonbirch

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Whirlpool Bitterness Discrepancy!!!
« on: April 30, 2018, 12:41:28 PM »
There seems to be a bitterness/ibu discrepancy between the android app and desktop editions of beersmith when setting a whirlpool time above 85c within the equipment profile on the desktop edition. So for example I have it set to 35 minutes, the desktop edition of a recipe im working on says 50.1 ibu?s where the android app says 60 ibu?s. If I untick the ?Estimate Boil hop util in whirlpool? box both the desktop and app have the same ibu?s. Which is correct? Thanks.

Offline rcjung

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Re: Whirlpool Bitterness Discrepancy!!!
« Reply #1 on: May 31, 2018, 04:02:10 PM »
verify in both OS if the equipament is the same

Offline dentonbirch

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Re: Whirlpool Bitterness Discrepancy!!!
« Reply #2 on: June 11, 2018, 12:34:55 AM »
Really surprised by the poor response to my support question!

Offline dentonbirch

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Re: Whirlpool Bitterness Discrepancy!!!
« Reply #3 on: June 11, 2018, 12:39:47 AM »
The recipe is in the cloud! I'm gonna guess the app is wrong and the desktop addition is closer to the correct ibu's.

Offline Oginme

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Re: Whirlpool Bitterness Discrepancy!!!
« Reply #4 on: June 11, 2018, 05:32:38 AM »
I don't have the app version, so cannot comment on the discrepancy between the two versions. 
 
To answer the question you raised in the original posting of "Which is correct?" the answer is most likely, neither. 

Tinseth is based upon a model developed by Glenn Tinseth on the system he brewed with many years ago using dried hop cones.  Depending upon the actual length of chilling as compared to the system Glenn used, your results will vary widely from his.

Rager follows a utilization curve which is just not normal for chemical reactions.

Neither modeled the utilization of whirlpool hop additions.

Even if the two pieces of software agreed, there would be only a slim chance if they gave the closest answer for your process.

To make matters even hazier, the calculation for IBU measures the amount of isomerized alpha acids at a wavelength where there is interference from other compounds in the hops which absorb at that frequency.  Further, there are other compounds in the hops, such as the beta acids which can contribute to the sensation of bitterness when oxidized and are not measured using the spectrophotometric method for IBUs.

You have narrowed the issue down to the way the two pieces of software calculates a value of continued IBU contribution of boil hops in the whirlpool.  Personally, I have that box unchecked as I know from experience what bitterness level I want to target for my process to get the bitterness sensation I aim to achieve.  In essence, this is the key:  Did you get the perception of bitterness that you wanted?  Once you can understand this hedonistic experience correlation to the IBU numbers, then you know where to set the value to get the bitterness experience you want in your beers.
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Offline brewfun

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Re: Whirlpool Bitterness Discrepancy!!!
« Reply #5 on: June 11, 2018, 08:22:18 AM »
In essence, this is the key:  Did you get the perception of bitterness that you wanted?  Once you can understand this hedonistic experience correlation to the IBU numbers, then you know where to set the value to get the bitterness experience you want in your beers.

^^ THIS!

Different hops have different bitterness "texture" on the palate. If I gave you a 100 IBU beer of all Horizon, you'd say "yeah, kinda bitter" but 100 IBU of Chinook and you'd ask for a tongue scraper. Mostly it's CoHumulone variations that make the difference, but other artifacts come into play, too.

Anecdotally, there are pretty consistent stories of brewers who get their 80 IBU beer lab tested and it comes back far below  what they thought. Yet, it tastes like an 80 IBU beer to them. From the sound of some posts, it appears brewers confuse IBUs with hop flavor, for which there is no scale. From my experience, and papers from University of Oregon, IBU calculations are most accurate under 20 and least accurate over 50.

The most important thing about bitterness is that hop isomers are hydrophobic. Yeast, foam, fermenter and tubing walls are all places isomers migrate towards. They look for every opportunity to get away from water.
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Offline Oginme

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Re: Whirlpool Bitterness Discrepancy!!!
« Reply #6 on: June 11, 2018, 09:58:38 AM »
More than anecdotal. 

Experimental Brewing did a full series with an American Pale Ale, IPA and DIPA and had their Igors send them the beers.  These were then tested for measured IBU content, along with a trained taster evaluating the IBU content by taste and a full set of hedonistic testing of both perceived bitterness and preferred bitterness.  Write up is at https://www.experimentalbrew.com/experiments/writeups/ibu-lie-kind

Among other aspects of their interviews with the Igors, the chilling time post boil stood out dramatically in most cases as a significant factor in the differences between planned and tested IBU.
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Offline jomebrew

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Re: Whirlpool Bitterness Discrepancy!!!
« Reply #7 on: June 11, 2018, 03:51:35 PM »
To the original question, I can't help because I'm not willing to pay for the mobile app.

On the topic if whirlpool IBU contribution, I've seen a a few charts to help understand IBU contribution such as this one form AHA
https://www.homebrewersassociation.org/how-to-brew/effect-post-boilwhirlpool-hop-additions-bitterness-beer/

I am not a member but I'd like to see this presentation https://www.mbaa.com/meetings/archive/2015/proceedings/Pages/65.aspx

Because of the subjectiveness of bitterness, that is 50 IBU to me is different than 50 IBU to you, I've always said that IBU is a reference point you establish what it means to you.  I know what calculated IBU level I like in my beers and base my hop additions around that number.  Because my whirlpool time where wort is above 160F is usually pretty short, I don't bother with the whirlpool IBU contribution.  At most that it a couple points.  When my whirlpool will be an hour, I will make sure to adjust my contributions to keep in in the range I want it.







Offline dentonbirch

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Re: Whirlpool Bitterness Discrepancy!!!
« Reply #8 on: June 22, 2018, 11:48:41 AM »
Well there's some interesting responses for me to mull over, thanks.

Offline dentonbirch

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Re: Whirlpool Bitterness Discrepancy!!!
« Reply #9 on: August 03, 2018, 09:03:36 AM »
So just to point out that the ibu's are identical when using Beersmith 3 desktop and Beersmith 3 android app, thanks for the fix Brad!!! Love the not so relevant answers above!!!

Offline dentonbirch

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Re: Whirlpool Bitterness Discrepancy!!!
« Reply #10 on: August 03, 2018, 09:06:46 AM »
It seems that Beersmith 2 desktop addition was deemed to be on the low side of the ibus!

 

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