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Author Topic: BJCP guidelines  (Read 3955 times)


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BJCP guidelines
« on: March 25, 2011, 05:45:25 am »
As I try to dial in some recipes to brew to BJCP style, I notice that the IBU's of the style do not change accordingly when I switch between Reiger and Tinseth in my brewing software.  However, depending on which I select, the expected IBU bitterness of a recipe does change, and I could be dialed in or 5-10 IBU off with the same hop addition.  Does anyone know if the BJCP guidelines use the Reiger or TInseth formula? 

Offline mabrungard

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Re: BJCP guidelines
« Reply #1 on: March 25, 2011, 06:30:03 am »
In my opinion, the IBU ranges in the guidelines are a little more aligned with the Rager equations.  But, we do know that the Tinseth equations are closer to the actual IBU levels in beer. 

I like Jamil's advice to adopt an equation and stick with it.  You become accustomed to the relative power of your equation and bias your hopping to that understanding.  I use Rager just because it seems to conform to the guidelines.  I used Tinseth for a couple of brews and found that they were significantly over bittered.  I just never bothered to accustom myself to Tinseth. 
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Re: BJCP guidelines
« Reply #2 on: March 25, 2011, 06:38:08 am »
I think you are exactly right.  I am in the process of deciding which to go with and then I'll stick to it.  I just want to pick the appropriate one for the BJCP style numbers that are locked in to all brewing software.

Offline dmtaylor

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Re: BJCP guidelines
« Reply #3 on: March 25, 2011, 06:38:23 am »
The actual IBU level of a beer can only be measured in a laboratory.  The BJCP guidelines provide ranges from actual laboratory data, not Rager or Tinseth formulas.  That being said, Tinseth is the most accurate of all the formulas.  And Rager is the one that a lot of people use largely because it's the one Jamil uses.  Personally, I like accuracy so I use Tinseth.  In the end, it doesn't matter much which formula you use as long as it's consistent.  But if you want to compare against BJCP guidelines, etc., then I really can't help but recommend Tinseth, as Rager is WAY off the true IBU values for many beers.

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Offline Tim McManus

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Re: BJCP guidelines
« Reply #4 on: March 25, 2011, 06:46:09 am »
I had the exact same question a few years ago and asked it on TechTalk.  This is the response I got from David Houseman on the issue:

+++begin Houseman


Why are you looking for formulae for IBUs in the BJCP style guidelines?
There are none.  No formula calculations.  The IBUs for the styles are
they are, independent of how someone arrives at them.   These weren't
calculated but rather are those that are historically, traditionally or
exist today in the best examples of the styles.   If you need formulae for
you to use in figuring out how to achieve those IBU levels in your system
then look at ProMash or a number of texts.   Ray Daniels' book, Designing
Great Beers, is a great read for looking at the ration of IBUs to starting
and finishing gravity.

David Houseman

[new message]


Thanks for the prompt reply.

I guess I'm having trouble correlating the IBUs in the BJCP texts to the IBU
formulas.  We do use BeerSmith, Promash and BeerAlchemy (Mac program) but
were unsure which formula would most closely align with the IBU ranges.

For example, we were designing a beer over the weekend that we have
previously made.  We wanted to reduce the hop bitterness from 100 IBUs to 75
IBUs.  We normally use Tinseth (74.5 IBU) to calculate IBU.  Daniels isn't
that far off Tinseth (76.6 IBU) at our volumes, but Rager (96.6 IBU) and
Garetz (63.9 IBU) are much different in their calculations.

If IBUs are subjective, then it just may be a matter of buying commercial
examples of a style, tasting them, and brewing test batches of beer to
determine which IBU calculation matches our palate.

I was just wondering if there was a correlation between the IBU calculations
and the BJCP values.

Thanks again for your reply.

[new message]

The simple answer is no.   What the BJCP is telling you is the appropriate
range of IBUs in a specific style.   How you get to that point isn't a BJCP
concern.  Use any formula that works for you to get to say 75 IBUs.   I use
Rager in Promash but have always had similar questions about which may be
more accurate.   That would be a good point for research.   But 75 IBUs is
75 IBUs.

+++end Houseman
Tim McManus
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