### Author Topic: IBU calculation error  (Read 562 times)

#### csu007

• Brewer
• Posts: 291
• Littleton, CO
##### IBU calculation error
« on: February 16, 2012, 09:53:28 PM »
so i have checked 3 different websites and i got 3 different IBU's (33.2, 48.9, 40.3)
my recipe was an extract milk stout

3.5 gal boil, 5 gal batch
.5oz styrian goldings 3.4% A.A. 60min
.5oz styrian goldings 3.4% A.A. 30min

estimated O.G. is 1.053 (wort is to hot to measure actual right now)

“Sometimes when I reflect back on all the beer I drank, I feel ashamed. Then I look into the glass and think about the workers in the brewery and all of their hopes and dreams. If I didn’t drink this beer, they might be out of work and their dreams would be shattered. Then I say to myself, “It is better that I drink this beer and let their dreams come true than be selfish and worry about my liver.

#### a10t2

• Official Poobah of No Life.
• Posts: 4330
• Ask me why I don't like Chico!
##### Re: IBU calculation error
« Reply #1 on: February 16, 2012, 09:58:55 PM »
Presumably three different correlations. What was the boil gravity? Tinseth gives 30 IBU assuming 1.075 in the kettle.
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Beer is like porn. You can buy it, but it's more fun to make your own.
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#### csu007

• Brewer
• Posts: 291
• Littleton, CO
##### Re: IBU calculation error
« Reply #2 on: February 16, 2012, 10:04:32 PM »
I did not take boil gravity reading , but my gut feeling is that 30ish should be closer to the correct IBU. thanks for the confirmation, the first site was the 33.2.
“Sometimes when I reflect back on all the beer I drank, I feel ashamed. Then I look into the glass and think about the workers in the brewery and all of their hopes and dreams. If I didn’t drink this beer, they might be out of work and their dreams would be shattered. Then I say to myself, “It is better that I drink this beer and let their dreams come true than be selfish and worry about my liver.

#### a10t2

• Official Poobah of No Life.
• Posts: 4330
• Ask me why I don't like Chico!
##### Re: IBU calculation error
« Reply #3 on: February 16, 2012, 10:06:42 PM »
All you need to calculate the boil gravity is the amount of extract and the volume of wort. If you added all the extract at the beginning of the boil, the SG was 1.075.
Sent from my Microsoft Bob

Beer is like porn. You can buy it, but it's more fun to make your own.
Refractometer Calculator | Batch Sparging Calculator | Two Mile Brewing Co.

#### csu007

• Brewer
• Posts: 291
• Littleton, CO
##### Re: IBU calculation error
« Reply #4 on: February 16, 2012, 10:40:27 PM »
Oh ok, thanks
“Sometimes when I reflect back on all the beer I drank, I feel ashamed. Then I look into the glass and think about the workers in the brewery and all of their hopes and dreams. If I didn’t drink this beer, they might be out of work and their dreams would be shattered. Then I say to myself, “It is better that I drink this beer and let their dreams come true than be selfish and worry about my liver.