[hopfenundmalz]

Hmmm. I recall Jamil saying a few years back that the difference between agitation and using pure o2 was negligible.

To get above 8 ppm you need O2. For most beers 8 is fine. The beers I use O2 on are lagers and really big ales.

Recently I stopped using O2 on many of my ales, as they were too clean, lacked esters. Something like a Ordinary Bitter benefits from the complexity that the esters add. Now I just pump into the fermenter, and the pumping adds enough O2 through splashing.

[euge]

I'm speaking past my pay-grade here, but for your lagers wouldn't a sufficiently large pitch accomplish the same thing? I've only been doing lagers for about a year now and they are improving. Lots to learn.

[erockrph]

I'm speaking past my pay-grade here, but for your lagers wouldn't a sufficiently large pitch accomplish the same thing? I've only been doing lagers for about a year now and they are improving. Lots to learn.

I don't know if it necessarily accomplishes the same thing, but I don't think the extra O2 is necessary for normal gravity lagers, either. Still, it certainly doesn't hurt as insurance.

What would accomplish the same thing (or at least something similar) is re-aerating about 12-18 hours or so after pitching, which is something I've had success with in the past with my high-gravity beers prior to getting an O2 setup.

[HoosierBrew]

I use a mix-stir until the foam rises to the top of the bucket - that has to be the max for aeration from standard air. I get solid, consistent fermentations, even on fairly high OG beers. But I do use a couple minutes of O2 through a wand for RIS, Wee Heavy, or Quad. I just don't think it's necessary for most beers.

[denny]

I'm speaking past my pay-grade here, but for your lagers wouldn't a sufficiently large pitch accomplish the same thing? I've only been doing lagers for about a year now and they are improving. Lots to learn.

Pretty much so.  The purpose of O2 is to allow the yeast to synthesize sterols.  They use the sterols to keep cell walls flexible to encourage budding.  If you pitch enough yeast that's not necessary.  However, there are consequences to beer flavor from yeast reproduction, so although you might get a fine fermentation from pitching more yeast, you might not end up with the same flavor to the beer.

[a10t2]

I personally don't think O₂ is necessary. Saturated DO levels using air are 9 ppm at 64°F and 13 ppm at 48°F. I consider those to be just right for ales and lagers, respectively, even if I'm only getting to 80-90% of the saturation limit using an air pump and stone. With pure oxygen and no DO meter, I doubt I could guess at the actual levels in the wort and get within even 50%.

As far as stones go, I do worry about sanitation, so I use these.

And Denny is right on (of course) about DO vs pitching rate and potential flavor impacts. Hence my reluctance to blindly use O₂.

[euge]

So it seems to be a matter of preference? The possible negative hinted at would be changing an established oxygenation process for a repeatable recipe.

[erockrph]

So it seems to be a matter of preference? The possible negative hinted at would be changing an established oxygenation process for a repeatable recipe.

That's how I feel. Basically, if it ain't broke, don't fix it.

FWIW, of all the equipment purchases/upgrades I've made, my O2 setup is the only one I feel wasn't worth the money. There are a lot of other things I wish I would have purchased instead.

[denny]

FWIW, of all the equipment purchases/upgrades I've made, my O2 setup is the only one I feel wasn't worth the money. There are a lot of other things I wish I would have purchased instead.

I purchased an O2 setup and used it until the little bottle ran out.  Since I hadn't seen any improvement over using my MixStir, I sold the O2 setup rather than buy another bottle.  A MixStir doesn't need refills!

[HoosierBrew]

FWIW, of all the equipment purchases/upgrades I've made, my O2 setup is the only one I feel wasn't worth the money. There are a lot of other things I wish I would have purchased instead.

  A MixStir doesn't need refills!

Sure doesn't !

[majorvices]

I've been doing a lot of flavor threshold experiments switching between using pure o2 and compressed air. Pretty sure I get better results, faster, stronger ferments that reach better attenuation faster with pure o2 for lagers. Ales may tend to lose a little bit of esters from the pure o2 but again, I see stronger, faster fermentation and better attenuation with pure o2 on ales as well. Still not sure which I like for ales yet but I know that I'm leaning toward pure o2. Yeast flavors may be cleaner but I think I like the results better.

I definitely agree with a second addition of compressed air after 12 hours for beer over 1.080. I see a much shorter fermentation time with crisper flavors with the second addition.

As always YMMV.

[klickitat jim]

Hmmm. I recall Jamil saying a few years back that the difference between agitation and using pure o2 was negligible.

I was listening to Brew Strong Aeration last night. I gathered that in their opinion splashing works but O2 is best. You have to avoid using too much, which he said is like wide open for five minutes.

For me, using the mix stir works. I haven't had as much varying results with ales as I do with lagers. I'm certain O2 in a repeated method that I can adjust will help. I also think that a sanitized stone or wand has to be more sanitary than blowing whatever is in my drill over the top of my wort. Especially if you use the same drill for milling. In not concerned about O2 cost if a $9 bottle lasts for ten batches. I've got 3 bottles, I'll just grab three more every time I get down to the last one.

I guess time will tell. I have no doubt that splashing works, I can always go back to that if I don't like O2.

[james]

IMO if you are repitching yeast or making big beers you definitely want to make sure they have sufficient o2 whether from o2 tank, shaking, etc.  If you are making normal strength beers (1.056ish) and not reptiching  dont worry about it much

[Joe Sr.]

I've been doing a lot of flavor threshold experiments switching between using pure o2 and compressed air. Pretty sure I get better results, faster, stronger ferments that reach better attenuation faster with pure o2 for lagers. Ales may tend to lose a little bit of esters from the pure o2 but again, I see stronger, faster fermentation and better attenuation with pure o2 on ales as well. Still not sure which I like for ales yet but I know that I'm leaning toward pure o2. Yeast flavors may be cleaner but I think I like the results better.

I definitely agree with a second addition of compressed air after 12 hours for beer over 1.080. I see a much shorter fermentation time with crisper flavors with the second addition.

As always YMMV.

That's interesting to hear.  I haven't done any side by side ferments, so it's hard to see the impact.

[klickitat jim]

IMO if you are repitching yeast or making big beers you definitely want to make sure they have sufficient o2 whether from o2 tank, shaking, etc.  If you are making normal strength beers (1.056ish) and not reptiching  dont worry about it much

I've been stir starting from smack packs then repitching out to 4 or 5 generations, before starting all over.

I don't think this is going to make a huge difference, but I'm kind of getting down to just small differences left to make. I'm kind of running out of process improvements to make.