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Hop Utilization percent of whole fresh hop cones.

RJKSKI

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Just made a batch of wet hopped IPA. I used 30 ounces of fresh wet hops in a 5.5 gal batch. Had the hops tested so I know the alpha and beta acids are close. recipe says the IBU should be 94. It's not even close. I'm assuming it's because the hop utilization factor of 100% is not right. Does anyone have an idea what hop utilization percent I should try for fresh wet hops added to a 5.5 gallon final volume batch. I added 6 ounce quantities at 45, 30, 15, 5 and then at 170 degree steep to 155. Excellent taste but no where near a 90 IBU ale.
 
In a little research into %AA testing of hops, it appears that the reported value of a % alpha or beta acids test in hops is on a dry basis.  You probably also got a % moisture test result back with your hop analysis, which is included because they need to dry down the hops to do the extraction and analysis of the hop oils.  Fresh wet hops are usually around 80% moisture, so the % AA of the hops you added would be about 1/4 of the number reported.  Since I don't have access to the actual test method and standard reporting format, you should probably contact the company which ran the testing for you and confirm.  Another way to determine this is to look at the %AA they reported against the %AA for dried cones or pellets of the same variety.  If the numbers are close, then the testing is on a dry basis.
 
I just looked up the ASBC method for testing of alpha and beta acids in hops.  It does require the hops to be dried (although it does not state so specifically), and ground to pass through a fine sieve before extraction of the hop oils and acids in solvent.  At 80% moisture, there is no way the hops would be able to be ground to 'powder' as the method states.  Just an update for your information.
 
I do understand that. I guess i wasn't clear on my question and the numbers I used were back calculated to 80% moisture. ie. i used 1.92% instead of the reported 9.6%. I normally use 100% hop utilization for hop pellets. Should i use a utilization rate of around 50% if I'm using fresh hop cones? What about dried hop cones? Is the utilization of whole cones that much different than the 100% generally used for pellets?
 
Thanks for the clarification.  BeerSmith differentiates between utilization based upon the hop type: leaf, pellets, plug, extract.  The leaf is as dried cones which does have a bit less utilization than the pellets or plugs and the program takes that into consideration based upon this setting. 

In terms of utilization of fresh (wet) hops, I've just scanned through several hundred papers on hops, alpha acid utilization, and isomerization of hop alpha acids, and did not come up with one article which addressed the utilization rate of alpha acids from fresh hop cones.  This does not mean that the information is not out there somewhere.

Sorry I could not be of more help.
 
I just spray it out until there is no visible hop material.  I dont worry about it too much because it gets boiled.
 
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