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Old 01-24-2009, 04:53 AM   #1
Oct 2008
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I am looking at some recipes and when it says 3 AAU of [insert hop type], what does that exactly mean? What kind of scale is it?
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Old 01-24-2009, 06:13 AM   #2
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Jan 2006
Santa Cruz, CA.
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AAU stands for Alpha Acid Unit. It is determined by the alpha acid % of the hop and the weight of the addition. It is better explained by John Palmer here

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Old 01-24-2009, 06:41 AM   #3
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Aug 2005
Torrance, CA
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AAU = Alpha Acid % (On hop Package) x Weight of hops (ounces)

A recipe calls for 10 AAU of Cascade

Your cascade says it's 5.0%, so to get 10 AAU, multiply the 5 by 2.

You need 2 ounces of cascade for that hop addition

if your hops were 4.0% you would need 2.5 ounces, if the AA% is 6.0 then you need 1.67 ounces.
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Old 01-24-2009, 01:36 PM   #4
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Feb 2005
Atkinson (near the Quad Cities), IL
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It's really simple math as Brewsmith already showed you.

If you have 3%AAU and the recipe calls for 4 use you calculator and press 4 divided by 3 equals 1.33 oz.

If you have 6.5%AAU and the recipe calls for 4 use you calculator and press 4 divided by 6.5 equals .61 oz.

See how simple it is?
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Old 10-11-2013, 01:41 PM   #5
Nov 2011
Biddeford, Maine
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So, I'm making an Imperial IPA and it calls for 20-25 AAU's for bittering hops of like Columbus, Warrior or Summit. If I take the Summit AAu of 18.5% and take the high end of the AAU's of 25 for the recipe, I come up with about 0.75 oz of hops for that boil of 60 min. Does that sound right?
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Old 04-15-2014, 07:33 PM   #6
Jan 2012
Warwick, NY
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I know this is late to the game, but I think abbysdad2006 has it upside down.

AAU = % alpha acid x ounces

So for 25 AAU from 18.5% Summit, 25/18.5 = 1.35 oz

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