Isomerized Kettle Extracts (PIKE)

Preparation:	pure resin extract undergoes controlled heating with alkali metal carbonate which isomerizes
Major Role:	provision of bittering and late hop character to beer
Method of Use:	addition to boiling wort in kettle at various stages

Composition
As for pure resin extract except that over 90% of the alpha acids are isomerized.
from supercritical CO2 extract:
	-	lacking in essential oil components
from liquid CO2 extract:
	-	more pure than supercritical
	-	containing essential oil amount and quality comparable with source leaf hop
Oils can be left in or removed during isomerization and left out or added back following isomerization

Advantages
-	very easy to handle, ship, store and use
-	allows precise control of bitterness
-	has very high utilization of bitterness (55 - 60%)
-	retains aroma properties of source hops (ex-liquid CO2)
-	high purity and freedom from residues
-	no wort losses
-	allows benefit of liquid CO2 extract use with no higher cost of bitterness than from leaf hops

Disadvantages
-	specific varieties subject to minimum notice and quantities
-	may be considered “chemically processed”

Composition