Consensus on pure O2 aeration

I recently got one of those pure O2 aeration systems and a disposable benzomatic tank. I want to know how long I should run it for. I have read many of the posts about this and have found times between 30 sec w very little flow, to a few minutes at full blast. So I figured I would be safe doing about 45sec, until the product showed up with directions that say to pump for 15-30 MINUTES. I just want someone who has done it a lot to tell me how long they do it. I assume the OG also is a factor. Like I said, I only did it for about 45sec last night, and then pitched a full yeast cake (O.G. was about 1.085). Am I good, should I do it some more?.... IM FKING TIRED OF OFF FLAVORS FROM SLOW FERMENTATIONS (that emoticon really expresses how I feel)

Well, I am sure that there are some real scientific numbers, but here's what I do.

First I use a stainless stone that I got from Austin Homebrew.
I sanitize the hell out of the stone and tube. I put it into the ferm, give the ferm a swirl, then open the 02.

You'll notice that the valve is a lot more like on/off than control.
You'll know when it is areating. When the "band" of areated wort reaches all the way around, or when foam reaches the top, your golden.

I just did one last night. Into the ferm @ 7:00pm, krausen at 8:00am, 1.060 w/ 1L starter. Every one I've done has been similar.

60 seconds per 5 gallons is plenty!

lrr81765 said:

When the "band" of areated wort reaches all the way around, or when foam reaches the top, your golden.

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I was wondering what that was. I saw the band afterwards, but I just bubbled until a bit-o-foam came out the top.

I'm gonna call fermentap and figure out why it says "you need a total time of about 30-120 minutes. We use 45 minutes for normal gravity worts (more for higher gravity worts)"

briewer2 said:

I'm gonna call fermentap and figure out why it says "you need a total time of about 30-120 minutes. We use 45 minutes for normal gravity worts (more for higher gravity worts)"

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I'd bet money those directions (30-120 minutes) are for "seconds", not minutes.

I hit my high-grav brews with 2 minutes of O2. latest edition of BYO mentions 2 minutes, as well.

been using the red tanks for years. Same as Irr81765 with cleaning, etc. While you can go for 'full blast' - that seems wasteful and inefficient, so I go for just visible bubbling from stone, and I go for 60 seconds.
Been getting decent starts, but I might bump up to 90 secs, to see if they start faster - usually about 24hrs w/o starter, 8-12 with.

briewer2 said:

I was wondering what that was. I saw the band afterwards, but I just bubbled until a bit-o-foam came out the top.

I'm gonna call fermentap and figure out why it says "you need a total time of about 30-120 minutes. We use 45 minutes for normal gravity worts (more for higher gravity worts)"

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My guess is that they are referring to using an aquarium pump versus pure O2. I takes longer if using an aquarium pump.

Yeah, is it possible the directions were in the bag with the tubing and diffusion stone and NOT the O2 regulator? 30 minutes would be for air pump, not pure O2. I used 60-120 seconds.

Hang Glider said:

been using the red tanks for years. Same as Irr81765 with cleaning, etc. While you can go for 'full blast' - that seems wasteful and inefficient, so I go for just visible bubbling from stone, and I go for 60 seconds.
Been getting decent starts, but I might bump up to 90 secs, to see if they start faster - usually about 24hrs w/o starter, 8-12 with.

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If you think about it, more oxygen should produce a longer lag time because fermentation doesn't begin until all the oxygen has been eaten up by the yeast. I think, the benefit of more oxygen is that it increases your overall cell count, because the yeast propogate while there is oxygen.

In practice, my longest lag times were experienced when i used o2

Side note: personally i only bother with o2 with bigger beers, i like to feed my wort air from a pump for 30 to 45 minutes after pitching.

I find my active fermentation does take a little longer when using pure O2, for the above mentioned reason that more O2 = more yeast growth first, and then fermentation kicks off rather explosively.

I go no more than 60 seconds of pure O2, just enough flow to disturb the surface and cause a little foaming.

briewer2 said:

IM FKING TIRED OF OFF FLAVORS FROM SLOW FERMENTATIONS (that emoticon really expresses how I feel)

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I'd be shocked if you could trace back an off flavor to slow fermentation.
Even if you are talking about lag time and not slow fermentation, how long are we talking and what off flavor (describe)?

olllllo said:

I'd be shocked if you could trace back an off flavor to slow fermentation.
Even if you are talking about lag time and not slow fermentation, how long are we talking and what off flavor (describe)?

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Well first of all my fermentation times are very inconsistent. But that is also because I am a new brewer and just started really paying attention to pitching rates. But I had a lot of weird flavors that taste like a combination of boozy (we foolishly started with high gravity beers) and unappetizing fruity esters that I have to imagine could be from temp fluctuations. I ferment in my bedroom which changes slightly, but never below 66* or above 73*. I think I just needed to improve my techniques on basic beers before trying advanced ones.

On another note, I started using O2 since my first post and I get a little longer lag (as you guys predicted) but when it starts, it STARTS. Woke up this morning with a air lock full of beer foam. Additionally, the first beer I did with o2 caught up to a beer I did five days earlier w/o o2. They are the same beer too, so Im interested to taste the differences. Ill update when I sample.

I have no exp. with aeration stones, so I can't speak to that, but typically,
off-flavors are due to variation in fermentation temps, or high fermentation temps. 66 F is on the high side for ales, from what I've observed. Low 60's are recommended.

If the room is low 60's or even High 50's, the wort can be a few degrees higher, so it's actually fermenting in the low 60s. I'd look into getting the temp down a few degrees. Try a large tub of water to put the bucket/carboy into and swap in and out bottles of ice.

My $0.02

JPicasso said:

Try a large tub of water to put the bucket/carboy into and swap in and out bottles of ice.

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Wow, that is one of the most simple but best ideas Ive heard in a while. I assume you mean just cycling plastic water bottle in/out of the freezer. Here im thinking about how much ice i need. Sounds good, but I think I am just going to put a a/c unit in my room cuz my central sucks. I think its my best bet since A) I like my room cold and B) I have 6 carboys going right now (i brew too much) so thats a lot of buckets. Thanks for the idea though, im lockin that one in the bank.

briewer2 said:

Wow, that is one of the most simple but best ideas Ive heard in a while. I assume you mean just cycling plastic water bottle in/out of the freezer. Here im thinking about how much ice i need. Sounds good, but I think I am just going to put a a/c unit in my room cuz my central sucks. I think its my best bet since A) I like my room cold and B) I have 6 carboys going right now (i brew too much) so thats a lot of buckets. Thanks for the idea though, im lockin that one in the bank.

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do a search on "swamp coolers" you will find everything you need to put this to work for you

I use pure O2 on all lagers and ales over 1.060, otherwise whipping it with a wine degasser seems to work just fine.

briewer2 said:

IM FKING TIRED OF OFF FLAVORS FROM SLOW FERMENTATIONS (that emoticon really expresses how I feel)

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Fermentation speed really doesn't indicate anything about if off flavors are developing. In fact a really fast fermentation is usually caused by high temperatures which absolutely will cause off flavors.