Hops AA%

HomeBrewTalk.com - Beer, Wine, Mead, & Cider Brewing Discussion Community.

Help Support Homebrew Talk:

sdclong

Member
Joined
Nov 30, 2012
Messages
12
Reaction score
0
Location
Cambridge
I've been brewing from kits for a while now, but I've decided to try an extract recipe I found on this forum. I live in a rural area with no LHBS, so I order most ingredients online. The hops' alpha acid percentages on the recipe are higher than I can find available online. So, noob question: is it okay to use a lower percentage of the same type of hops? or is it better to use a different type of hops with the same percentage as the recipe calls for?
 
Joined
Oct 8, 2008
Messages
5,639
Reaction score
2,861
Location
Groton
Use the hop variety from the recipe at the lower AA% but just use more of it to achieve the proper IBUs. This is where brewing software comes in handy. You might also look up substitutions that might be closer to the AA% of the hops in the recipe. Another thing to consider is to not get too hung up on the IBUs being exactly as they are in the recipe. There's so many variables that affect it and the human tongue can only differentiate between a finitely small change in bitterness anyway, so as long as you're in the ballpark you'll be fine.
 

Calichusetts

Well-Known Member
Joined
Nov 16, 2011
Messages
3,022
Reaction score
537
Location
Plymouth
If you do not have brewing software use the HBU system (homebrew bittering units)

It works like this: AA% multiplied by the hop amount in ounces

So if the recipe calls for 10%AA in the amount of a 1/2 ounce. That is 5 HBU.

If your hops are only 5%AA then you would have to use 1 ounce to get the same bitterness. Its really simply math and works like a charm. Hope this helps
 

RM-MN

Supporting Member
HBT Supporter
Joined
Nov 26, 2010
Messages
14,516
Reaction score
5,274
Location
Solway
Most of the hops used for bittering leave little flavor or aroma when the beer is finished so you can do some substitutions to get the alpha acid percentage you want. Some hops will be a little "smoother" than others. I did find that Citra seems to keep some of its aroma throughout the boil. I like Citra so I didn't consider that a problem.
 

logan3825

Well-Known Member
Joined
Sep 6, 2010
Messages
1,029
Reaction score
53
Location
Madison
I would try to get the AA units for the 60m addition close but just worry about the weight to the 20m and later additions.

AA units are calculated by multiplying the AA% by the weight. Then you can divide the AA units by AA% to get the weight you need.
 
OP
S

sdclong

Member
Joined
Nov 30, 2012
Messages
12
Reaction score
0
Location
Cambridge
Thanks for all the help! I used more for the 60m to make up for the lower %, but the 20m and 5m called for .5 oz saaz 5.8% and all I had was 3.4%... didn't have enough to add extra, so I used what I had. Hopefully it won't turn out too bad.

:)
 

RM-MN

Supporting Member
HBT Supporter
Joined
Nov 26, 2010
Messages
14,516
Reaction score
5,274
Location
Solway
Your late addition hops add little to the bitterness but are there for flavor and aroma so the alpha acid percentage isn't as important.
 
Top