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BYO or Beersmith IBU Calculation, which is correct?

ivectoryou

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Hi.

I brewed 10 gallons of Janet's Brown Ale (recipe in the October 2009 issue of BYO).  I doubled everything because the recipe is for 5 gallons and I brewed 10 gallons (all grain).

The recipe in BYO states "IBU = 63."  

Beersmith states "Bitterness (IBUs) 31.6"

I doubled all of the hop additions and I've checked my math.  I'm sure it's something simple, but I can't for the life of me figure it out.  

The recipe is for a 90 minute boil, with the first hops going in the mash and the last being the dry hop.

My OG and FG are real close to the BYO recipe.  I got a little better efficiency than the 65% they base their recipes on (I got 68%).

Anyway, here are the BYO hop additions followed by what I have entered into Beersmith.

.83 oz at 6.5% alpha acid, Northern Brewer (Mash Hop)              
1.04 oz at 6.5% alpha acid, Northern Brewer (60 Min)
.83 oz at 6.5% alpha acid, Northern Brewer (15 min).
1.25 oz at 6% alpha acid, Cascade (10 min).
1.25 oz at 6% alpha acid, Cascade (0 min).
1.67 oz at 9% alpha acid  Centennial (dry hop)

My additions as entered into Beersmith.  Remember, I doubled the amount of hops because my batch size was 10 gallons and theirs is for five gallons.

1.66 oz Northern Brewer (6.50% Alpha Acid) Mash Hop
2.08 oz Northern Brewer (6.50% Alpha Acid) 60 Min
1.66 oz Northern Brewer (6.50% Alpha Acid) 15 Min
2.50 oz Cascade (7.00% Alpha Acid) 10 min
2.50 oz Cascade (7.00% Alpha Acid) 0 min
3.34 oz. Centennial (7.80% Alpha Acid) Dry Hop

Now that I write this, I think I am on to what might be the issue.  I entered the 10 min and 0 minute additions as "Aroma Hop-Steep" in Beersmith and I'll bet it doesn't consider
those additions to contribute any IBU's to the beer.  Aren't hops added that late just for aroma?  Why would BYO count all the hops towards IBU's, even if they use a different scale
than Beersmith uses?

I just changed the 10 min addition to be listed as a "boil hop" in Beersmith and the total recipe IBU's are now up to 41.2.  Beersmith shows no IBU's contributed from the "0 minute
addition and no IBU's contributed from the "Dry Hopping."  From what I remember reading, I believe that is the way it should be.

Does anyone have any idea why my #'s are so far off from theirs?

Thank you for your time.



 

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RandomSF

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It would be helpful for you to export the recipe and attach it to this thread.  Maybe you overlooked something that someone else might find.
 

ivectoryou

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RandomSF said:
It would be helpful for you to export the recipe and attach it to this thread.  Maybe you overlooked something that someone else might find.

Good idea.  I just edited my original post and attached the file to it.  Please let me know if I didn't do that correctly.  Thanks.
 

MaltLicker

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I believe 5 of the 6 hop additions are entered as "leaf" in your BSmith.  If the BYO recipe is not based on leaf, that could be some of it.  The default setting in BSmith is a -10% on leaf utilization, and a whopping -80% for the mash hop addition.  If you'll really using pellets for most/all of these additions, you'd have to change each line item in the recipe; you'd see about a 10% increase.  

Some of your later AA% are actually higher than BYOs, so you'd have to verify all those numbers too.  

You'd have to verify what hops model BYO used:  Rager, Tinseth, etc., as well.  


PS - You can enter a recipe verbatim to ensure it is correct, and then use the 'scale' function to double the batch size (or whatever increase/decrease you want).  You'll get some odd amounts that you may want to round off, but at least you know you had their recipe perfect before changing volumes or efficiency for your local setup. 
 

ivectoryou

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Hmm.  I used all leaf hops with this recipe, so it should have been 6 of 6.  I am aware that using pellets vs. leaf and the different hop formula's could make a difference, but I was doubtful that it could make a difference of roughly 40 IBU vs. 60 IBU.  Are you also saying that I get 80% less out of my mash hop addition due to the fact that I used leaf and they likely used pellets?  Yikes.  When I get this figured out, I will still likely use leaf hops and just compensate.  They just seem to work so much better with the Blichmann 20 Gallon BK I have.  Pellet hops clog the Blichmann screen (even though I put the pellet hops in those small nylon fine mesh bags).

Lastly, I really like your idea of entering the recipe as a 5 gallon recipe and then scaling it up to 10 from there.  That's much easier than figuring it myself.  Thanks for that hint!

Any more ideas on this problem would be helpful from anybody who might be able to clue me in.  I guess my next step would be to find out what BYO uses and enter the recipe in Beersmith using the same thing they use and see if it's close.  If not, either Beersmith or BYO has a mistake. 



MaltLicker said:
I believe 5 of the 6 hop additions are entered as "leaf" in your BSmith.  If the BYO recipe is not based on leaf, that could be some of it.  The default setting in BSmith is a -10% on leaf utilization, and a whopping -80% for the mash hop addition.  If you'll really using pellets for most/all of these additions, you'd have to change each line item in the recipe; you'd see about a 10% increase.  

Some of your later AA% are actually higher than BYOs, so you'd have to verify all those numbers too.  

You'd have to verify what hops model BYO used:  Rager, Tinseth, etc., as well.  


PS - You can enter a recipe verbatim to ensure it is correct, and then use the 'scale' function to double the batch size (or whatever increase/decrease you want).  You'll get some odd amounts that you may want to round off, but at least you know you had their recipe perfect before changing volumes or efficiency for your local setup. 
 

MaltLicker

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ivectoryou said:
Are you also saying that I get 80% less out of my mash hop addition due to the fact that I used leaf and they likely used pellets?

No, just that the default setting in BSmith for mash hops (any form) is a -80% on bittering utilization.  "The default adjustment calculates mash hops as having 80% less utilization (-80%) than boiling hops the equivalent time."

Frankly, that seems dubious to me, in that alpha acid extraction occurs thru boiling, and mash-hopping is done at mash temps (~153F), or much less than boiling.  How does any isomerization occur at 153F, steeping in hot wet grains? 

Perhaps BYO assumes even more bittering from that mash hop than BSmith? 
 

Wastegate

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MaltLicker said:
Frankly, that seems dubious to me, in that alpha acid extraction occurs thru boiling, and mash-hopping is done at mash temps (~153F), or much less than boiling.  How does any isomerization occur at 153F, steeping in hot wet grains? 
The higher ph contributes to AA extraction. It only takes a few points to make a big difference. Also in order to get full isomerization of the hops AA it must be boiled. Hot water works also, just not as well as boiling.

As for the discrepancy in the AA between the two, The only thing I can see is it may be a misprint on BYO's part (meaning BeerSmith is correct). I don't see it. You may want to write them and ask if it was a miss-print. I will go look at that issue when I get home tonight.

Cheers
Preston

Vacation time= missed forum time :(
I'm glad to be back...
 

ivectoryou

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Maltlicker and Preston,

Thanks for the replies.

I will find out which IBU scale BYO was using to come up with that total IBU # and then I will enter the recipe exactly has they have it listed.  If there is still a major difference in the total IBU, I will contact them and find out which of the two is in error.

UselessBrewing said:
MaltLicker said:
Frankly, that seems dubious to me, in that alpha acid extraction occurs thru boiling, and mash-hopping is done at mash temps (~153F), or much less than boiling.  How does any isomerization occur at 153F, steeping in hot wet grains? 
The higher ph contributes to AA extraction. It only takes a few points to make a big difference. Also in order to get full isomerization of the hops AA it must be boiled. Hot water works also, just not as well as boiling.

As for the discrepancy in the AA between the two, The only thing I can see is it may be a misprint on BYO's part (meaning BeerSmith is correct). I don't see it. You may want to write them and ask if it was a miss-print. I will go look at that issue when I get home tonight.

Cheers
Preston

Vacation time= missed forum time :(
I'm glad to be back...
 

ivectoryou

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I entered this recipe exactly as it appeared in Brew Your Own.  I chose pellet as the type of hops and even changed the formula to Rager.  Even with the changes, Beersmith still calculates the total IBU's as 47.4.

A nice lady who works for BYO promised to contact the author of the article (Jamil) to see if their stated IBU's was a misprint and then get back to me.

I'll post what I find out after I get the call from BYO.

 

MaltLicker

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Agreed.  I entered it and got the boil-off, pre-boil and OG, and SRM to match up, and also got 48 IBUs. 

The version in his book has slightly different hop amounts and also says 63 IBU, despite the different boil volume in the book.  If you change the mash hop to a boil hop, it jumps to 67.  63 IBU would also make for a  0.95 BU:GU ratio, while the style indicates a range from 0.44 to 0.66.  (48 IBU would be a more logical 0.72 for this big brown.)
 

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ivectoryou

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Thanks for the info.  I noticed in your recipe, you show the primary fermentation as 14 days.  The other day I was down to 1.015 after only 6 days in the primary, so I went ahead and dry-hopped it the next day.  I think the new oxygenation stone w/pure O2 bottle really helped this fermentation go quick and strong.  I'm sure the starters made on stir-plates didn't hurt either.  It sure tastes good and I can't wait to try the finished product.



MaltLicker said:
Agreed.  I entered it and got the boil-off, pre-boil and OG, and SRM to match up, and also got 48 IBUs. 

The version in his book has slightly different hop amounts and also says 63 IBU, despite the different boil volume in the book.  If you change the mash hop to a boil hop, it jumps to 67.   63 IBU would also make for a  0.95 BU:GU ratio, while the style indicates a range from 0.44 to 0.66.   (48 IBU would be a more logical 0.72 for this big brown.)
 

ivectoryou

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Update:  The nice lady from Brew Your Own Magazine called me back after she had spoke to Jamil Z. about this issue.  She explained that Jamil said that it's probably just a difference in brewing software used and to just go ahead and brew the recipe as published in the article (which I had already done).  I'm sure it will turn out great.  It tasted good when I sampled it after a hydrometer reading the other day (only 6 days after brewing it).

I'll probably post this on www.homebrewtalk.com and see if other brewing software comes up with similar #'s as Beersmith.

ivectoryou said:
I entered this recipe exactly as it appeared in Brew Your Own.  I chose pellet as the type of hops and even changed the formula to Rager.  Even with the changes, Beersmith still calculates the total IBU's as 47.4.

A nice lady who works for BYO promised to contact the author of the article (Jamil) to see if their stated IBU's was a misprint and then get back to me.

I'll post what I find out after I get the call from BYO.
 

MaltLicker

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Very interesting.  Confirms for me that these hop utilization models (Tinseth, Rager, etc.) and even these software packages each are providing their best prediction of things, and are entirely dependent on the data we enter.  Sounds like JZ uses ProMash/Rager which has different settings for mash-hopping.  (I generally get very close to his book recipes, most of which don't mash hop.) 

And, the effect of mash-hopping and the effect of first-wort hopping are variables that we can change.  We can alter those variables to suit our personal experience, but we'd have to know them from the source to perfectly duplicate a recipe's numbers.  (I personally enter FWH at -10% rather than +10% because I think the smoother bittering reduces the perceived bitterness.) 

The other hidden math aspects include the assumptions about boil evap rates taking the volume from the pre-boil figure down to the final boil volume.  Each evap rate would create different points along the boil volume curve, at which the hop utilization model factor would be different.  And if we over/under collect the boil volume starting point, that's yet another variable.  Thank goodness it makes beer regardless. 
 
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