Originally Posted by Bobby_M
Here's an idea. Just use a "little" more hops in your first boil to conpensate for the slight reduction in utilization ( I don't know the math but maybe 20% more). That pot will end up way bitter and then mellow when it's blended with the unhopped portion.
I Do mine like this. I have 5.5gal pot so I can get 5 gallons in so I usually have about 1 to 2 gallons depending on the size go in 3.5 gal pot. I just use beer tools to figure out the hopping. It always seems to turn out fine. I am sure this in not the most accurate way to do it but it works. If you are not supper anal about your hopping it will all work out just fine.