IBU question

[hoppybrewster]

I got a Amarillo Pale Ale extract kit as a gift, don't really use kits but it was the right price:

6 lbs golden light LME
1 lbs golden light DME
8 oz caramel 40L
8 oz carapilis 6 row
1/2 oz Columbus 60 min
1 oz Amarillo 20 min
1 oz Amarillo 0 min

The kit instructions say I'd end up with a 44 IBU.

I plug the recipe into Beersmith using a style of American Pale Ale and I end up with an IBU of 24.6. Who's right? What should I do? Leave it alone?

 

[bajaedition]

what is the AA% of the hops?

IBU should be (OZs x AA x Utilization) / (gallons of wort x 1.34)

 

[BeerLoverHere]

It all depends on the alpha acids in the hops. You can toy around with your hop additions in Beer Smith to get the IBU you desire.

 

[hoppybrewster]

The Amarillo is 8 1/2% and the Columbus is 13 1/2.

 

[hoppybrewster]

what is the AA% of the hops?

IBU should be (OZs x AA x Utilization) / (gallons of wort x 1.34)

Do I use this formula for each hop addition of all kinds of hops then add them together? What is utilization?

 

[Calder]

BeerSmith uses 3 different methods to calculate the IBUs; Tinseth, Rager, and Garetz. None of them are right, and all 3 will give you very different results. You have to tell BeerSmith which one to use.

It is not surprising that you can't get an accurate calculation, as everyone's process is different. Most people get used to using just one as it seems to be close to what they produce. Personally, I prefer Rager.

 

[hoppybrewster]

BeerSmith uses 3 different methods to calculate the IBUs; Tinseth, Rager, and Garetz. None of them are right, and all 3 will give you very different results. You have to tell BeerSmith which one to use.



It is not surprising that you can't get an accurate calculation, as everyone's process is different. Most people get used to using just one as it seems to be close to what they produce. Personally, I prefer Rager.

So now what? Do I just trust the 44 IBU that the kit says?

 

[hoppybrewster]

Can some one please answer my question above^^^^^^^on how to use the hop formula properly?

 

[bajaedition]

I get over 56 on just the columbus, not even having added the amarillo, with the amarillo I am just over 77
I am either doing this wrong or both the numbers you got are wrong
could very likely be me

utilization is the percentage of the hops that get used, a 60 minute boil is 25%
a 15 minute boil is 5%

there are charts for that

 

[bajaedition]

this site

http://www.brewersfriend.com/ibu-calculator/

gives me another answer 68,49

the search goes on

 

[hoppybrewster]

this site



http://www.brewersfriend.com/ibu-calculator/



gives me another answer 68,49



the search goes on

That a pretty cool tool! I used it and came up with 29. Problem is who's right? This tool or the kit info?

 

[bajaedition]

29?

i used it and got well over 70

I think the tool is right

anyway

 

[hoppybrewster]

29?



i used it and got well over 70



I think the tool is right



anyway

What did we do different?

 

[bajaedition]

What did we do different?

View attachment 172254

my bad, I was usung a 6.5 gallon boil and a full oz of the first hops

I misread the first post I think

egg on my face

 

[Calder]

Have you compared the additions in BeerSmith? There is a page/menu-item called 'Hops bitterness'.

I put in your numbers from above and got the following:

Tinseth - 25 IBUs

Rager - 35 IBUs

Garetz - 21 IBUs

Most people use Tinseth or Rager when formilating recipes.

If I assume a full 5 gallon boil, I get; T - 41, R - 45, G - 27. It looks as though the IBUs were calculated assuming a full boil.

 

[hoppybrewster]

Downloaded BrewersFriend and plugged the recipe in. Here ya go.





It was set for Tinseth.