Originally Posted by AnOldUR

This experiment being done with extract is not valid for AG brewers and can be misleading. The same effects of break material are not present when using extract.

Originally Posted by AnOldUR

Gravities effect on hop utilization (for AG brewers) is similar to its effect on ABV. Higher ABV comes from attenuation not the actual gravity, but few would argue that higher gravity beers generally produce more alcohol.

Originally Posted by jkarp

Yes. This has already been said several times in the thread.

Originally Posted by Ouroboros

It may not impact utilization, but a partial boil might limit the maximum IBU's you can achieve in your brew. I think I read somewhere that the iso-alpha acid content of some of the stronger IIPA's approaches the solubility limit. If that's true, you might not be able to brew very bitter beers with a partial boil.

If you're only boiling (and hopping) half of your final volume, your final brew can be no more than half-saturated with iso-alpha acids. Unless you do some sort of workaround like adding hops when you boil the water that you're going to be adding the wort to.

As an anecdote, I did soomething along those lines with an IPA before I got myself a stainless 30 qt brew kettle and had good results as far as bitterness goes. Just bottled it and I drank a glass green and flat I was pretty good on Franziskaner by that point... it seemed like a great idea at the time. I swear my farts smelled like Citra hops today.

Originally Posted by jkarp

The BYO / BB experiments proved this untrue, or at very least that the max solubility of AA in wort is much higher than everyone thinks. Their experiment beer was a high-IBU IPA. Partial boil made no difference at all.

Originally Posted by Ouroboros

Cool... like I said... I just read it somewhere that very bitter IIPA's were nearly saturated. Nice to see people addressing these questions experimentally.