Hot Wort Aeration

Another thread got me thinking about what's giving a "wet cardboard" taste in my beers. I've ruled out just about everything but someone mentioned hot wort aeration. I did some reading and found this chapter in John Palmer's book. http://www.howtobrew.com/section1/chapter6-9-3.html

Question is.. Can HWA occur while boiling? Is too much aggressive string during boil able to cause this? How about directly after boil?

My process so far (and its been the same for all 4 of my extract brews) has been to remove my 5 gal from the boil and immediate start the wort chiller while whir-pooling pretty aggressively.

 

Boiling drives off O2. That's why you need to aerate your wort somehow after it's cooled to provide needed oxygen to the yeast. It's ok to stir post-boil, but you don't really want to froth it up. At least not until it's below 80 degrees and you're ready to pitch your yeast.

 

Do a search here at HBT for Hot Side Aeration although I think the first post in this thread does a good job of summary

http://www.homebrewtalk.com/f14/post-boil-hot-side-aeration-b-s-262787/