The July-August BYO had a project for a simple bronze T that holds a SS aeration stone for introducing O2 into the cooled wort as it passes from the CF chiller. I basically made the same setup but coming out of the kettle post whirlpool chiller a la Jamil and gravity fed. I had just gotten my O2 tank so I tested all of this on yesterday's batch. The only issue I had, aside from not having good control over the regulator, was the fact that running the O2 for the prescribed 1-2 minutes puts a damned small amount of O2 in contact with the wort. (It takes several more minutes for the wort to get into the fermenter). I did gas the first part of the wort that went into the fermenter, so I'm hoping that the O2 in the head space along with the stream of wort splashing into it will do a good job. Any thoughts? I'm at 24 hours and still haven't detected CO2 coming from the lager I'm doing. Can't see what it's doing either as the fermenter is not translucent and I haven't opened it up (yet). Thanks as always, J

Sorry--I should have said it puts a small amount of wort in contact with the O2, not the other way around.

I have a small tank, a regulator, hose, and stone. I sanitize the stone and hose with 'one step' and stick the hose deep into my wort just before I pitch. (and yes that sounds NC-17) I usually run it for one minute and let the O2 bubble up from the bottom of the bucket. I don't bother controlling it, I open it up WOT and let it rock. Not fancy at all but it works, even on huge beers. My O2 tank has lasted over a year.

A day for a lager to start fermenting? Don't worry.

Zane, thanks for the reply which did help me relax. Anyway, I just wanted to report back that the O2 did seem to make a positive difference (over the previous slosh between buckets method). This was my best lager fermentation to date with the S-189 getting the gravity from 1.050 down to 1.008 in about 11 days. Slow but very steady and with absolutely no sweetness in this German Pilsner when I checked the FG

I use a medical oxygen tank with a regulator bought off ebay. I do what Zane does, stick the stone into the wort but I set the flow at .5 liters. I get a lot of foam at higher settings. I do think this makes a differences in the the final gravity of the brew. I've done this to a Pliny elder clone and a hoppy pale ale. Both finished at or below the projected gravity. I also pitched two packs of dry yeast so that had something to it.

I'm thinking that putting an O2 stone down into the bottom of the fermenter will reach planty of wort so only a 2 minute blast is needed. Direct injection will require more because the O2 only sees a small amount of wort until the fermenter gets closer to being full. O2 is cheap if you're using a welding bottle and not the hardware sized bottle so using extra does not really impact the wallet and wont hurt the beer.

And yes, having a head space full of O2 will help as it will absorb into the beer as the yeast feed on what's already there.

start the o2 injection about midway through the kettle draiin

Jamil maintains that the stone in the fermenter is just to get the wort moving into contact with the headspace. Thus as O2 is heavier than air, I'd think that early blasts of O2 would provide the headspace that the later wort will fall into and provide turbulence for.