alpha acid %

there was a thread with a formula that would compensate the % difference in the hops, but i cant find it!! haha.

what i need to know is the formula. the recipe calls for a higher AA% than the hops i have.
thanks!

Not sure about the thread, but the easiest thing would be to covert everything to AAU's (alpha acid units). Each % of AA per oz = 1 AAU. For example, if the recipe calls for 2.5 oz of 7.5% AA hops, that's 18.75 AAU's (2.5x7.5), so you'd divide 18.75 by the AA% of your hops to get the weight you need to use. If your hops are only 6%AA, then you'd use 3.125 oz (18.75/6). I guess the formula would look like-

Weight X AA% = AAU

or

Weight = AAU/AA%

It's really simple math...

Let's say a recipe calls for 8 AAU and your hops are 5.4.

8 / 5.4 = 1.48 oz (I'd round up to 1.5 oz) of your hops.

If a recipe calls for 4.2 and all you have is 7.1...

4.2 / 7.1 = .59 oz (I'd round up to .6 oz).

However, do not adjust the flavor and aroma hops.