hot wort aeration

[Padalac]

Hey guys.. I've been thinking about wort aeration vs oxygenation a little bit and it got me wondering.

The main issue seems to be that churning the hell out of your wort with a power drill and a mash paddle or paint stirrer is going to aerate the beer well but its also going to pull air from the room into the beer including whatever dust is in that air and all the wild yeast and microbes that come with that.

Now I've heard recently that hot-side aeration causing off-flavours is a bit of a myth..

Is there any other reason why we can't aerate the wort prior to chilling it? Does the action of the boil drive oxygen out of solution? If that's the case can wort absorb enough oxygen after flameout but before I turn on the chiller?

[Kev888]

Boiling does remove much of the dissolved oxygen, yes, so people generally aerate/oxygenate it again before pitching; supposedly its not as important with dried yeast but I tend to anyway, and its important with liquid yeast. I believe its hard to get much oxygen dissolved by aerating the wort at near-boiling temperatures though, which is one reason people do it whilst cool.

I also wouldn't say the HSA thing is 'entirely' a myth - aeration of warm wort can cause oxidation; however as mentioned its less easy when near-boiling and the actual effects of HSA seem to have been greatly exaggerated in the past. So personally I don't get paranoid about it, but nor would I try to intentionally oxygenate the wort when hot.

You may want to investigate using an aquarium air pump and filter to remove spores etc, which you could use once the wort had cooled (obviously, being careful with sanitation). Or the bees knees would be an oxygen cylinder and regulator, used to briefly bubble pure oxygen through it.

Cheers
Kev