I kegged a kolsch about 3 weeks ago that was supposed to be around 24 IBUs (.75oz of German Perle for 21 IBUs and .5oz Czech Saaz for 4 IBUs). Right after I kegged the beer I noticed that I only used .25oz of Perle, which equates to around 11 total IBUs. I have since used the remaining .75oz of Perle for another batch, however, I have plenty of other hops available.
What would be the best way to make up for the missing 13ish IBUs?
"Once in a while you get shown the light, in the strangest of places if you look at it right"