[Slackjawls]

im fermenting a 1.097 imperial stout.  I pitched 12 hour ago and want to add more o2.  Would you add it to the headspace or get the stone down into the wort?

[Steve Ruch]

im fermenting a 1.097 imperial stout.  I pitched 12 hour ago and want to add more o2.  Would you add it to the headspace or get the stone down into the wort?

Into the wort. I don't think that adding o2 to the head space would do much good.

[Slackjawls]

Any opinion on how much? Its 2 1/2 gallons of 1.097 OG wort.  I was thinking 30 seconds at 1 liter per minute.

[brewinhard]

Any opinion on how much? Its 2 1/2 gallons of 1.097 OG wort.  I was thinking 30 seconds at 1 liter per minute.

1.097 is not THAT massive of an original gravity. Are you not observing any fermentation going on? Why do you think the wort needs more oxygen?  Did you provide ample aeration at pitching time?

[blatz]

Any opinion on how much? Its 2 1/2 gallons of 1.097 OG wort.  I was thinking 30 seconds at 1 liter per minute.

that's awful vigorous in my experience, unless my regulator is faulty - 1 LPM is usually wasting a lot of O2 for me.  I'd do 1/4 LPM for may 30-45 sec and see how frothy it gets, I'm guessing you don't even get that long.

[Slackjawls]

Brad Smith interviewed the guys from imperial yeast recently and one of them said you should give a second dose to anything over 1.080. Ive read and heard this several times.  I aerate before pitching and I aerated my starter.  Im just looking to see what other experienced brewers are doing to hopefully avoid unnecessary mistakes

[Joe Sr.]

I know some people do it, but I've never added O2 after pitching.  Most of my beers are in the 1.08+ range.  IMO, aeration at the outset and a big healthy pitch of yeast will get you what you need.

But, if you choose to go with a second does of O2 I would use a very low flow rate.  I try to set it so I can just see the bubbles coming out of the stone.  If the surface of the wort is roiling, your flow rate is too high.