Originally Posted by jcaudill
I mean this in the nicest way possible: I don't care how sterile you think this is. It's not. Once you get the wort below 180 risk goes substantially up. That's one reason we boil or we could just go right from mash to fermenter (besides the isomerization of hops).
The risk for infection goes up, you have hot-side aeration which can lead to off-flavors, and precursors for acetaldehyde go way up. There is a reason commercial brewers don't do this. You shouldn't either. Just aerate cooled wort.
+1 on the hot side aeration being an issue (an issue over 80° I believe). Making sure I didn't aerate too hot made a pretty decent difference in the final taste of all my beers.
On a side note though, I think there's quite a few more factors to the boil than sterilizing and hop use. You've got color change, dms boil off, and protein/tannin clumping (hot break) for a few big processes.
Either way, off topic. If you did figure out an inline aeration process, you'd need to sterilize it somehow without aerating hot wart.