My thinking so far on this involves reserving a portion of the wort from the boil to start with, and then adding it back in later. The exact best way to go about this is the question I'm asking. Let's say for argument that the volume is 2 gallons. So I produce 13.5 gallons of wort, reserve 2 gallons, and start the boil with 11.5 gallons in the kettle; a perfectly safe boil volume. When should I add back the 2 gallons? Should I try to boil it for a while or just simply add it back at the end so that is has boiled some? Should the reserved wort be the same strength as the other wort or should it be the last runnings? The amount of sugar in the wort will have an affect on IBU calculations and hop utilization so would I be better off with the most sugar in the main boil?

Any ideas to point me in the right direction would be great!