Yah, that's a better idea Denny, but my actual question is about the less than 60 minute hops. Do those leave oils that continue to isomerize and become bitter with the extended boil time, or is this not the case because that actual hop matter has been pulled?
I'm theorizing that those oils which contribute the aromas and flavors are still sitting in the wort and that the extended boil time would move them from there to a bittering like addition. Probably not to the same extent as if the actual hops where still in contact, but surely some of those chemicals have gone into solution and will continue to be modified by extended boil time.
We're talking about 2 different things here. Any alpha acids in the wort will continue to isomerize, and the bitterness will increase as well. Any hop oils that would contribute to flavor and aroma will continue to be driven off by the boil.
In the end, I would expect more hop bitterness and less hop flavor and aroma.