Hot Side Aeration...is it debunked at the home brew level?

There is a debate in my home brew club about hot side aeration.  Many of our brewers feel that it is a debunked myth at the homebrew level.

I'd like to hear the thoughts of others on this issue.

Unless they are making light colored, light flavored beers with a 6 month, unrefrigerated shelf life, I'm on the side of debunked. If someone's chilling method was pouring hot wort from bucket to bucket over and over, then yeah, there's a case for HSA.

That said, there is nothing wrong with reducing aeration with hot wort. Personally, I'd spend a lot more effort reducing aeration/oxidation while racking, kegging and bottling.

Some of the systems I've worked on should have produced a lot of HSA, but it never revealed itself. Like the vourloff picture below. A system I used about 5 years ago.

I saw a PBS show about Brooklyn Brewery and they were blowing the mash from the "mash sitting tun" to the "mash lautering tun"  with a huge pump.  If that didn't cause HSA, then I thought on the homebrew scale and with a modest amount of care, we were not at much risk. 

Well mostly debunked, at the mash level you do not boil at boiling the wort that act alone drives off O2. Transfer and add O2 during cooling? I do not get the myth water boils because of O2 and temp plus how high above sea level you are perhaps the myth is best left to Mythbusters? But I'd say a wild ass guess trend by the web.in the early days.

PaKettle said:

Well mostly debunked, at the mash level you do not boil at boiling the wort that act alone drives off O2. Transfer and add O2 during cooling? I do not get the myth water boils because of O2 and temp plus how high above sea level you are perhaps the myth is best left to Mythbusters? But I'd say a wild ass guess trend by the web.in the early days.

Click to expand...

PaKettle-

I don't think you understand the chemical processes that CAN result in off flavors from HSA.  It is a real thing.  There are numerous published papers on it.  The question is whether it happens significantly enough to result in off-flavors that reach a human taste threshold.  The answer to that seems to be "no."  But, that is not because its a myth, but because the standard homebrew processes don't expose the wort to enough oxygen at vulnerable times.

If you used a wire wisk or an industrial mixer to whip your mash into a froth, or injected oxygen into your wort at 160F after the boil for an hour, then you might have a real chance of experiencing the flavor effects of HSA.  Since very few people use these types of methods, HSA essentially does not occur on the home brew scale.  Plus, we generally make very flavorful beers with lots of malt, and significant hopping schedules. 

On the other hand, if you were making vast quantities of a very low flavor, watery lager.....and had massive pumps pushing hot wort around the facility, then any mixing of the hot wort with o2 and the resultant chemical reactions and flavors might be a cause for concern.

I err on the side of caution.  I use an immersion chiller and I very gently stir my wort to keep it moving, but I try avoid creating bubbles until my wort gets down to about 100F.  Once it gets to 100F, I stop worrying about oxygenation.

I use an aquarium pump once my wort is in the fermentor at my pitching temperature and I aerate with the pump for 25 minutes.  It's my understanding that with an aquarium pump, you can't over aerate.  To battle contamination, I try to get it into the fermentor as quickly as possible, I put the pump to it and put the lid loosely on top of my bucket primary during the aeration process.