hops by percentage??

Hi All does anyone know the best way to work with percentage of hops.  I know how to adjust grains by percentage but I do not see an option for hops.  The recipe I am working on calls for:

Cluster Hops.............48.8%
Brewer's Gold............25.6%
East Kent Goldings....25.6%
TOTAL.......................100%

to achieve an IBU of 62

Thanks
Bob

That kinda doesn't make any sense.  The IBU is not the only thing that counts, but also the aroma and flavor.  How many IBU did the Cluster hops contribute at 60mins vs 5minutes?  Was EKG just for aroma or was some added at 15mins?

If that is all the info you have from the recipe, then you don't really have anyway of accurately reproducing the beer that they are describing.

It would be good to know starting gravity and boil time, but assuming 1.050 and 60 minutes boiling, you can plug the recipe into BeerSmith and add 2 oz of Cluster, 1 oz of Brewer's Gold, and 1 oz of EKG, then reduce the time for the BG and EKG until you hit 62 IBUs. I was able to hit 61.2 with 2 oz Cluster for 60 min, 1 oz of BG for 15 min, and 1 oz of EKG for 5 minutes. You can emphasize Cluster by adding it for 20 min, BG for 60, and EKG for 15. All additions assumed the default AA% in BeerSmith and a 2 oz/1 oz/1 oz ratio for Cluster, BG, and EKG.

Of course there are other ways to approximate 62 IBUs, depending on what hop flavors you want to emphasize. More info would help a lot!