How to adjust ammount of hops according to Alpha Acids - Home Brew Forums

 Home Brew Forums > How to adjust ammount of hops according to Alpha Acids

09-07-2009, 06:15 PM   #1
chemman14
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Mar 2009
Newbury Park, CA
Posts: 1,649
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I just recently bought brewing classic styles and the recipes give you the alpha acid of the hops and the ibu's from each hop addition. In the book it says to adjust the amount of hops according to their actual alpha acids, but doesn't tell you the equation. How do you do this? and are there any calculators available?

09-07-2009, 06:30 PM   #2
jasonsbeer

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Jul 2009
Central Iowa
Posts: 390
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I've been using the beer recipator The Beer Recipator - Home.

There is a section in the spreadsheet to help you figure out how much you should add and when to get the desired IBU.

09-07-2009, 06:43 PM   #3
chemman14
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Mar 2009
Newbury Park, CA
Posts: 1,649
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hmm, OK but an equation would be idea that way I can figure out how much I need to buy at my LHBS

09-07-2009, 06:47 PM   #4
ISLAGI
1 beer short of a sixer

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Nov 2008
Frogtown, OH
Posts: 380
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My method is straight ratio method... I think it is similar to the BU method...

If the recipe calls for 1 oz of hops @ 8% (1 x 8 = 8 BUs) I would substitute 1/2 oz of 16% or 2 oz of 4% (.5 x 16 or 2 x 4 = the same 8 BUs).

Generally, if the AA% of the hops I have is within 10% of the % called for in the recipe, I ignore the difference, as long as my recipe still falls within category guidelines.

NOTE: This only refers to bittering amounts that I use as the 60 min addition. Changing the amount of hops by large amounts will likely change the flavor profile of the finished beer.

(Adding this, because you got a post in while I was typing)

Most likely, your LHBS is only going to sell by the oz. so that won't matter to your buy, unless it forces you up to the next oz.
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09-07-2009, 06:48 PM   #5

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Jan 2009
Kingston, PA
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AA% x (oz. of hops)=AAU(alpha acid units)

10%AA x 2 oz=20 AAU
8%AA x 2.5 oz=20 AAU
5%AA x 4 oz=20 AAU

See where I'm going with this?
This is a good way to adjust hops compared to your recipe.
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Quote:
 Originally Posted by dfc Things are going great too. I think I've only punched her in the face 3 times!
FERMENTING: Heady Topper Clone?
CONDITIONING: 40 gallons KBS clone in a Jim Beam Barrel (since 11/24/12)
DRINKING: Smoked Robust Porter, Orange Coriander Pale Ale #5
THINKING: first foray into lagers?

09-07-2009, 07:19 PM   #6
chemman14
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Mar 2009
Newbury Park, CA
Posts: 1,649
Liked 37 Times on 33 Posts

Quote:
 Originally Posted by annasdadhockey AA% x (oz. of hops)=AAU(alpha acid units) 10%AA x 2 oz=20 AAU 8%AA x 2.5 oz=20 AAU 5%AA x 4 oz=20 AAU See where I'm going with this? This is a good way to adjust hops compared to your recipe.
ah sweet thats what I was looking for. Thanks!

09-08-2009, 12:01 AM   #7

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Jan 2009
Kingston, PA
Posts: 1,761
Liked 41 Times on 35 Posts

No problem.
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Anybody can be a rockstar when the rest of the room is wearing helmets and drooling on themselves.

Quote:
 Originally Posted by dfc Things are going great too. I think I've only punched her in the face 3 times!
FERMENTING: Heady Topper Clone?
CONDITIONING: 40 gallons KBS clone in a Jim Beam Barrel (since 11/24/12)
DRINKING: Smoked Robust Porter, Orange Coriander Pale Ale #5
THINKING: first foray into lagers?

09-08-2009, 03:42 AM   #8
homebrewer_99

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Feb 2005
Atkinson (near the Quad Cities), IL
Posts: 17,796
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Here's what I do:

If the recipe tells you to use 8.4% and all you have is 5.7 just divide 5.7 into 8.4 to see how many of the 5.7 you have to use...in this case 1.47 oz.

Same goes the other way...recipe says 5.7 and you have 8.4...8.4 into 5.7 = .67 oz (of the 8.4).

Simple math, really. I think this is more like what you're looking for.
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09-08-2009, 03:44 AM   #9
bluestarlee
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Sep 2009
bluestarlee
Posts: 1

Thanks for the suggestion, I wish it had worked.

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09-08-2009, 04:04 AM   #10
homebrewer_99

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Feb 2005
Atkinson (near the Quad Cities), IL
Posts: 17,796
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Quote:
 Originally Posted by bluestarlee Thanks for the suggestion, I wish it had worked.
You wish what had worked?

Welcome to the forum!!
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