Iso-Alpha Acids - Beer/Wort
As heat is applied to hop alpha acids, they begin to bend or "isomerize", this process which occurs in the boil, and perhaps at other times, flame-out etc. This is what adds the bitterness to beer/wort.
These iso-alpha acids can be analyzed in wort or a final beer product to accurately quantify the amounts of these bitter compounds. This test can be used for hop efficiency and/or utilization rates.
Approximately 1ppm of iso-alpha acids = 1 IBU
IBU's are analyzed by a "Spec" assay which is non specific, this test uses HPLC to separate, isolate, and quantify accurately these bitter compounds.
Results are expressed as ppm of iso-cohumulone, and ppm of iso-n+adhumulone.
Sample size - 2oz.
Turnaround - Standard 3-4 days
RUSH - 1-2 days