Lowering IBUs

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beekeeperman

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Can I lower IBUs in a extract kit by boiling the bittering hops say 45 mins
instead of 60 ?
The kit is a 6.5 abv with 75-80 IBUs. 2 oz. Columbus is the bittering hops.
Would it affect the balance of the beer by lowering the IBUs to around 50 - 60 IBUs?
 

mkopec1

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I dont see why not. Balance is subjective unless youre some national beer judge that judges beer on style, etc... Thats the beauty of brewing your own beer, you brew it to your liking.
 

RM-MN

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Use only one ounce of Columbus, cut the IBU's in half. 90% of the bittering is done in the first 30 minutes so cutting the boil time from 60 to 45 minutes will have minimal effect.
 
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beekeeperman

beekeeperman

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Use only one ounce of Columbus, cut the IBU's in half. 90% of the bittering is done in the first 30 minutes so cutting the boil time from 60 to 45 minutes will have minimal effect.
OK thanks that makes better sense than my idea.
So, if 90% of the bittering is done in the first 30 mins why do the kits say boil for an hour i wonder ?.
I usually add most of the extract toward the end of the boil so why not shorten the boil time down to say 40-45 mins. ?
The late addition hops are all added within the last 10 mins. of the boil.
 

downzero

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80 IBUs is high for American IPA. I agree with the result you're trying to get. I'd reduce the 60 minute addition to 1 ounce or so and throw the rest in at 5 minutes (or even flameout).
 
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Background: why 60 minute boil? Perhaps because, by convention, most "all-grain" recipes (and kits) are 60 minute boil. For many all-grain recipes there are simple conversions to extract+steep recipes. So many extract+steep recipes have a 60 minute boil.
I usually add most of the extract toward the end of the boil so why not shorten the boil time down to say 40-45 mins. ?
If I'm doing a longer boil (to boil off the 'aroma' and 'flavor' oils in the hops), a 30 minute boil gives me good results. For me, a 30 minute boil seems to require about 30% more hops for the same IBUs (or 30% less IBUs for the same hops).

There is also the idea of a 15 minute boil:
 

Hoppy2bmerry

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Can I lower IBUs in a extract kit by boiling the bittering hops say 45 mins
instead of 60 ?
The kit is a 6.5 abv with 75-80 IBUs. 2 oz. Columbus is the bittering hops.
Would it affect the balance of the beer by lowering the IBUs to around 50 - 60 IBUs?
You could get the free trial https://www.brewersfriend.com/ and change amounts or boiling time to see how the IBUs will change if you have a malty wort you want somewhat high bettering to balance it, but you also have your own tastes. I was once surprised to hear the IBUs of Guinness stout drought as it has very little bitterness.
 

bleme

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Use only one ounce of Columbus, cut the IBU's in half. 90% of the bittering is done in the first 30 minutes so cutting the boil time from 60 to 45 minutes will have minimal effect.
^This^ and, if it suits the style, pitch the other ounce at 5min or flame out.
 
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beekeeperman

beekeeperman

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Background: why 60 minute boil? Perhaps because, by convention, most "all-grain" recipes (and kits) are 60 minute boil. For many all-grain recipes there are simple conversions to extract+steep recipes. So many extract+steep recipes have a 60 minute boil.


If I'm doing a longer boil (to boil off the 'aroma' and 'flavor' oils in the hops), a 30 minute boil gives me good results. For me, a 30 minute boil seems to require about 30% more hops for the same IBUs (or 30% less IBUs for the same hops).

There is also the idea of a 15 minute boil:
Really liking the idea of a 15 min boil. Think I'll try that cascade pale ale recipe on my next IPA brew.
That hour long thing I've always done is a bit too long.
Thanks for the links...
 

RM-MN

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OK thanks that makes better sense than my idea.
So, if 90% of the bittering is done in the first 30 mins why do the kits say boil for an hour i wonder ?.
I usually add most of the extract toward the end of the boil so why not shorten the boil time down to say 40-45 mins. ?
The late addition hops are all added within the last 10 mins. of the boil.
There are reasons for the 60 minute boil. It utilizes all the hop bittering. Less time is impossible to be certain the amount of bittering even if I say that 90% of the bittering is done in 30 minutes. Maybe it takes 35 for some varieties of hops or maybe some only need 22. At 60 you can be sure all the bittering is done.

Boiling for 60 minutes also reduces the amount of wort and concentrates it as you boil off more of the water. It also encourages more darkening due to the Maillard reaction.

With all that in mind, I rarely boil my wort for more than 30 minutes as I know I will have the right amount of wort at the end and I will be satisfied with the bitterness level.
 

TheMadKing

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There are reasons for the 60 minute boil. It utilizes all the hop bittering. Less time is impossible to be certain the amount of bittering even if I say that 90% of the bittering is done in 30 minutes. Maybe it takes 35 for some varieties of hops or maybe some only need 22. At 60 you can be sure all the bittering is done.

Boiling for 60 minutes also reduces the amount of wort and concentrates it as you boil off more of the water. It also encourages more darkening due to the Maillard reaction.

With all that in mind, I rarely boil my wort for more than 30 minutes as I know I will have the right amount of wort at the end and I will be satisfied with the bitterness level.
To add to this, boiling hops for 60 minutes also allows a number of chemical reactions to take place with the hop polyphenols (metal chelating and antioxidants), as well as protein breakdown and pH changes.
 

dmtaylor

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Can I lower IBUs in a extract kit by boiling the bittering hops say 45 mins
instead of 60 ?
The kit is a 6.5 abv with 75-80 IBUs. 2 oz. Columbus is the bittering hops.
Would it affect the balance of the beer by lowering the IBUs to around 50 - 60 IBUs?
Yes, this will work. However to get the reduction you are looking for you might want to reduce the boil time of the hops not just to 45 minutes but perhaps to 30-35 minutes. Based on real science, compared with 100% of the intended IBUs @60 minutes boil time, you'll get:

85% @45 minutes
80% @40 minutes
74% @35 minutes
69% @30 minutes
63% @25 minutes
57% @20 minutes
49% @15 minutes
40% @10 minutes
34% @ 7 minutes
29% @ 5 minutes
17% @ 2 minutes

Admittedly it becomes far less accurate below about 15 minutes, but you get the idea.

This is another tool in the toolbox.
 
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