IBU confusion?

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Fat boy quiff

IBU confusion?

Post by Fat boy quiff » Wed Jan 31, 2018 12:51 pm

Hi all, I am about to attempt a recipe from the brewdog catalog (Vermont IPA V2) . It has a whole load of hops in it but only one hop (Chinook) that is in the boil, which it says middle. The other 7 additions are end of boil and FV. The recipe comes as a 25ltr boil volume and a target OG of 1066' and the IBU is stated as 35. My question is, how do you achieve an IBU of 35 when if you put these figures into a hop calculator with a 45 min boil, you get something like 1.51 IBU's ?

Manngold
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Re: IBU confusion?

Post by Manngold » Wed Jan 31, 2018 2:16 pm

Might be wrong...but my understanding is that you can use a calculator (you can probably find it in beersmith), to input the hop details and AA% of the hop, and then work out how many grams you need to add to achieve that IBU. The other end of boil additions should not add much in terms IBU if they are added at flame out/zero minute additions. The dry hops will not add any IBU either.

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Re: IBU confusion?

Post by Manngold » Wed Jan 31, 2018 2:21 pm

Just looked at the recipe on DIYdog,

HOPS
(g) Add Attribute
Chinook 1 Middle Aroma
Chinook 20 End Flavour
Amarillo 30 End Flavour
Simcoe 30 End Flavour
Citra 50 FV Aroma
Amarillo 50 FV Aroma
Mosaic 50 FV Aroma
Simcoe 50 FV Aroma

It gives the following, is this what you were going to follow? 1g Chinook in the middle of the boil?

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Re: IBU confusion?

Post by orlando » Wed Jan 31, 2018 2:39 pm

Manngold wrote:
Wed Jan 31, 2018 2:16 pm
The dry hops will not add any IBU either.
The evidence for whether that is still true is changing. Studies are suggesting that dry hopping CAN increase IBU's. Bitterness perception is more important than some laboratory measurement but my own sensory evaluations led me to believe for sometime that boiling wasn't the only source of "bitterness".

As to the question, I used a calculator to hit the overall recipe IBU of an Elvis Juice clone, adding the "middle" hops at a time that got me there. Given that spotting differences in IBU (+/- 10) is not particularly easy for normal humans I wouldn't sweat it too much.
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Re: IBU confusion?

Post by joe1002 » Wed Jan 31, 2018 2:43 pm

The end of boil hops will contribute to the bitterness. I once brewed a beer with 0 hops in the boil however I chucked 200g in at flame out (it was Victoria's Secret IIRC) and that had plenty of bitterness. The recipe calculator won't calculate any IBU's for the flame-out hops though.

Fat boy quiff

Re: IBU confusion?

Post by Fat boy quiff » Wed Jan 31, 2018 3:04 pm

Manngold: Yes thats the recipe I'm looking at.
That was my understanding that flame out and dry hop additions add very little bitterness. So, would the answer be to increase the amount of hops and time until the IBU target is reached even if it means not following the recipe precisely ie not just middle of the boil, perhaps from start of boil. Even then you would have to add more hops than is stated. Makes you think when the recipe is created they should just state which hops and the IBU required?

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Re: IBU confusion?

Post by McMullan » Wed Jan 31, 2018 3:25 pm

Follow the recipe, FBQ. I've found the nicest American IPAs (for me) tend to be those calculators work out to be 'low' for IBUs :wink: Tweak it when you know for sure it's not what you were after.

McMullan

Re: IBU confusion?

Post by McMullan » Wed Jan 31, 2018 3:28 pm

Manngold wrote:
Wed Jan 31, 2018 2:21 pm
1g Chinook in the middle of the boil?
:?

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orlando
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Re: IBU confusion?

Post by orlando » Wed Jan 31, 2018 4:03 pm

joe1002 wrote:
Wed Jan 31, 2018 2:43 pm
The recipe calculator won't calculate any IBU's for the flame-out hops though.
BeerSmith now has a setting that accounts for some bitterness in the Whirlpool. It's under Options - Bitterness.
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Re: IBU confusion?

Post by joe1002 » Thu Feb 01, 2018 2:35 pm

orlando wrote:
Wed Jan 31, 2018 4:03 pm
joe1002 wrote:
Wed Jan 31, 2018 2:43 pm
The recipe calculator won't calculate any IBU's for the flame-out hops though.
BeerSmith now has a setting that accounts for some bitterness in the Whirlpool. It's under Options - Bitterness.
Ah, thanks for enlightening me. It's bugged me for a while.

Fat boy quiff

Re: IBU confusion?

Post by Fat boy quiff » Mon Feb 05, 2018 12:27 pm

I put this recipe into brewers friend IBU calculator as per the brewdog recipe. 25l boil,20l volume, 1g Chinook 14.6% AA,40 min boil time and it comes out at 1.44 IBU, far from the 35 IBU perported by the recipe. This is my dilemma and I wonder if it is an error?

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Re: IBU confusion?

Post by Laripu » Mon Feb 05, 2018 1:35 pm

Fat boy quiff wrote:
Mon Feb 05, 2018 12:27 pm
I put this recipe into brewers friend IBU calculator as per the brewdog recipe. 25l boil,20l volume, 1g Chinook 14.6% AA,40 min boil time and it comes out at 1.44 IBU, far from the 35 IBU perported by the recipe. This is my dilemma and I wonder if it is an error?
Sounds like a misprint in the recipe.
Even for a high alpha hop like Chinook, 1g is a negligible quantity. Try 28.35g, which would be 1 ounce. Maybe when the recipe was converted from Formerly British units to metric the unit was changed but not the quantity? Quick and dirty mental arithmetic: 1 ounce for 40 minutes should yield around 40 IBU.
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Fat boy quiff

Re: IBU confusion?

Post by Fat boy quiff » Tue Feb 06, 2018 1:22 pm

OK, for the first time ever, today I used an on line beer calculator (Brewers Friend). I started with the only boil hop in the recipe which was the 1g Chinook and ignored the others which were whirlpool and dry hop editions. I just upped the amount of hops until I reached the 35 IBU stated in the recipe. I then proceeded to add the other hops and to my surprise the IBU's were way up! After adding all of the other hops I then reduced the Chinook boil hop until I reached the required IBU of 35. Bearing in mind that I have scaled up 3.3 times for my 65l plant, The final amount of Chinook required was 3g! Well well well, what a surprise, technology hey.

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