[chinaski]

I bought some CO2 extracted hop concentrate recently and the label says 49.98% AA and the volume is 10 mL.  All of the calculato's that I've found on-line to figure out how much to use to get 35 IBU into a 5-gallon batch of ale do not account for %AA for some reason.  I find this strange as there are many extracts on the market for different hop varieties that vary in % AA.  I'm having a hard time figuring out how much to use.  Anyone know more about this?

[erockrph]

I've only ever used Hop Shot, and I stick to the rule of thumb of 1 mL = 10 IBU in 5 gallons of 1.050 wort, when boiled for 60 minutes. I generally only use it in IPA's with a whole lot of late hops, so hitting a specific IBU number is less important to me. I generally add 3 mL at 60 minutes for a 3 gallon batch in the 1.055 range, and let my whirlpool hops carry the rest of the IBU's.

I'm sure the actual AA% becomes quite important in a commercial brewery trying to replicate a recipe. At the homebrew level I don't know if that level of precision is necessary (or even possible TBH). Even after an hour of boiling, I still see a fair amount of hop extract globules floating around, leading me to believe that utilization isn't necessarily consistent.

[chinaski]

I've only ever used Hop Shot, and I stick to the rule of thumb of 1 mL = 10 IBU in 5 gallons of 1.050 wort, when boiled for 60 minutes. I generally only use it in IPA's with a whole lot of late hops, so hitting a specific IBU number is less important to me. I generally add 3 mL at 60 minutes for a 3 gallon batch in the 1.055 range, and let my whirlpool hops carry the rest of the IBU's.

I'm sure the actual AA% becomes quite important in a commercial brewery trying to replicate a recipe. At the homebrew level I don't know if that level of precision is necessary (or even possible TBH). Even after an hour of boiling, I still see a fair amount of hop extract globules floating around, leading me to believe that utilization isn't necessarily consistent.

Thanks for the reply.  I have used HopShots in the past so I'll use the same rule for my next IPA brew.  If it's off, it's off.