Cedar Rapids Brewing Society

I have a beer that I miscalculated the bittering hop addition, and need to increase the bitterness so that it can be drinkable.

looking into it I can make a hopped starter that I boil for 60 minutes (alpha acids need to be isomerized) and adding this to the keg.

Since IBU's units are mg/liter, can I make a 0.5 gallon starter at 200 IBU, and add it to the 5 gallon keg for an increase of 20 IBU's [10:1 dillution] or is there something else I'm forgetting?

Other option would be to add some isomerized hop extract, The drawback being the realitively large quantity that would need to be purchased, 1oz.

Have you looked at HopShots?

yeah I initially thought about them, but they are not isomerized so they need to be boiled. In other words it would be similar to dryhopping.

The only other option is isomerized hop extract. Joe can order in but its 1 oz jars [~$25-30], and I think its only good for a couple months in the fridge. Plus I would only be using a drop or two.
http://www.hopunion.com/1020_Isomerized ... fm?p4=open