[HoosierBrew]

FWIW, I've used O2 through a wand and had good results. But I'm using the mix stir now on all my beers (even on BIG beers), and can't tell any difference in attenuation or overall beer quality. The key being to aerate until the foam is at the top of the bucket. I'd be curious how this method compares with O2 analytically, but since I can't find (or measure) any difference I'll stick with it.

[Wort-H.O.G.]

Little red can and wand...60 sec for avg gravity ale, 90 seconds for average gravity lager. Never let it get more than a slight surface ripple...long and slow.

[Statsmats]

http://www.brewangels.com/Beerformation/AerationMethods.pdf

I've posted this before but it's interesting.  As you all will see there were some limitations to the experiment and it didn't test using pure oxygen, but makes me question whether I even want to buy O2 aeration equipment, something I've been strongly considering lately.

Edit:  it does mention over oxygenation is bad but doesn't indicate what that level of oxygen saturation is.

Thanks for the article link bboy...just read through and I have a couple takeaways:

1) High airflow rates (near 1.0 L/min) were significantly better (faster) at increasing the oxygen levels than low airflow rates (near 0.1 L/min).

2) Aeration stone (2 um pore) also improves ability to increase oxygen levels

3) Rocking and shaking was quicker than pumped air aeration...looks like it starts to level off at 10 minutes

In addition, the article states "...and there is some risk of toxicity to the yeast from over-oxygenating wort. Saturating wort with pure oxygen is likely to be toxic to the yeast." Hmmm...that statement appears to conflict with the Wyeast website (http://www.wyeastlab.com/hb_oxygenation.cfm) which states "Some yeast strains have higher oxygen requirements than others.  It is generally safe to assume that you need at least 10ppm of oxygen.  10ppm will supply adequate oxygen in most situations.  Over-oxygenation is generally not a concern as the yeast will use all available oxygen within 3 to 9 hours of pitching and oxygen will come out of solution during that time as well.  Under-oxygenation is a much bigger concern."

So...maybe you really can't over oxygenate (at least near the levels achievable by a brewer's typical or normal means).

Where does this leave me? Next time I think I will oxygenate first, then pitch the yeast...and going to run oxygen at 1 L per minute for 60 seconds - 90 seconds depending on the gravity. And pick up a wand to replace the aquarium stone (stone will be the backup or I can use to oxygenate my minnows).

Thanks for all the help everyone!

[JT]

I recall a brewer on another forum emptying an entire red can of oxygen into his wort on accident.  Likely the speed at which he was pumping the o2 in prevented it from staying in solution.  He didn't note any off flavors, but I'd hardly recommend it!  In short, the article referenced may be correct if you could actually saturate the wort with oxygen but Wyeast is also correct when stating it isn't really a concern. 

[jjflash]

I use in-line oxygen and a high quality Hach dissolved oxygen meter in the fermentor to establish my baseline O2 levels.  (All my beers start out >1.080.)  I am amazed how quickly the oxygen comes out of solution once transfer is complete and the O2 sat begins to plummet at 65 degrees.  This has prompted me to quickly pitch my yeast without delay.  Oxygen toxicity?  Doubt we can perform this feat with our equipment. All that extra oxygen is just leaking into the surrounding atmosphere.