Hop help?

[eapoll11]

I saw a thread on here a while ago that has the calculation to figure out the amount of hops to add to match a recipes hops with different aa's. Can anyone post that or explain it to me? Thanks!

 

[jerbrew]

Weight * AA = AAU

Example:
First hop
AA = 10 weight= 1 ounce AAU=10
AA * W = 10AAU

Substitute:
AA = 5
10AAU (what you want)/5AA = 2 ounces

I'd typically only use this for bittering. Anything flavor/aroma wise I'd do a 1:1 swap since isomerizing AA isn't your main concern.