Adding oxygen during fermentation

[Rick_R]

From a different thread, but posted here so as not to hijack the other:

Revvy: Evidently now the big thing is after 12 hours of fermentation to actually give your fermenter another minute of O2

Based on what I've thought true, that goes against all that is good and holy -- coming from a Rev, that's particularity appalling.

But, seriously, is that now understood as a good practice? If so (and it's not that I'm doubting what you heard, just fishing for other opinions), obviously swirling won't introduce additional oxygen -- so I assume it is an air stone and either an aquarium pump or O2 cylinder.

Rick

 

[Revvy]

I just heard it last week on Basic Brewing radio...It was in the NHC follow up. Shocked the crap out of me when I heard it...

It was during the I-view with Chris White from White Labs.

Considering he makes the yeasts, methinks he'd know.

July 3, 2008 - NHC Wrapup Pt. 1
Steve joins James as they begin their collection of interviews gathered from experts at the National Homebrewers Conference in Cincinnati. This week: Dave Wills, Michael Ferguson and Chris White.
http://media.libsyn.com/media/basicbrewing/bbr07-03-08nhcwrapup01.mp3

It's about 3/4's of the way into the I-view...

Considering he says that we need 10-12 PPM's of oxygen for good fermentation and vigorous shaking is only good for 2 ppm's, hitting a stuck fermentation @ under 10-12 hours with a minute of O2 may be may be just the thing. Especially for really big beers.

New info comes out all the time...Even John Palmer has gone back on what he wrote about IBU's after going to a confrence on hops....And a lot of the stuff we come to believe as 'conventional wisdom' is wrong anyway, yet we perpetuate it...

 

[malkore]

Revvy,

I'll listen to it at some point...but are they saying this only has merit if you did NOT do a pure O2 injection at pitching?

I do inject O2 at pitching, and usually have decent lag time since the yeast has 'all that oxygen to grow with'. Then I have stellar fermentation for 48-70 hours, and always reach my estimated terminal gravity, with no off-flavors in the beer.

It seems I'm doing nothing wrong, per my particular process...think I really need to 'fix' it?

 

[FlyGuy]

This is an accepted practice, but specific to high gravity beers and only before active fermentation begins (typically within the first 12 to 18 hours). When the yeast are still in their lag/growth phase, they need a lot of oxygen, and it is hard to get enough into solution in a high gravity brew, even with an oxygenation setup. But if you add it in two 'doses' you can get a lot more into solution. Since the yeast are are actively metabolizing O2 in the lag and growth phase, all of that O2 will get scavenged quickly, provided you do it before they hit active fermentation. If timed correctly, there is little worry of oxidation.

 

[Revvy]

Revvy,

but are they saying this only has merit if you did NOT do a pure O2 injection at pitching?

No he's saying that in beers above 1.060 sg, you give it another blast for 1-2 minutes between 10-12 hours after pitching....

My opinion? If it ain't broke, don't fix it, if you haven't had any problems with your method then keep doing it, unless you want to experiment....I will say that after hearing that, instead of giving my last beer only a minute of O2 before pitching, I gave it 2...I had krausen in about 8 hours

The reason I posted it in the context of the other thread was because we have this fear of oxydation (and other things)...and I've heard on an earlier Basic Brewing that the PPM's needed to actually cause oxydation in the homebrewing enviroment is quite high (again it is different for commercial brewers of BMC where any flavors are verboten (good or bad) and that level exceeds that which can happen in normal brewing situations and most accidents, for example all the times people panic because their autosiphon stalls and they have to pump it a few times.

I think it was in an I-view with Palmer where he said really, to oxydize your homebrew, you would have to literally empty your bottle of O2 into your bottling bucket before you have to worry about oxydation....

I think it's one of those RDWHAHB situations where things that are of concern to BMC brewers and Lagerers, like HSA, or Autolyses get transfered into the Homebrew community, and everyone starts worrying about stuff, that we really shouldn't.

I look at what White said this way...If an extra 2 minutes of pumped oxygen within the 10-12 hours of fermentation won't hurt my beer, then if I accidently rack into my bottling bucket a bit too vigorously than normal, I'm not going to lose sleep over it (or start an "is my beer ruined?" thread) about it....I'm not going to do it intentionally, mind you, but I'm not going to stress the accidents that happen.

 

[FlyGuy]

If an extra 2 minutes of pumped oxygen within the 10-12 hours of fermentation won't hurt my beer, then if I accidently rack into my bottling bucket a bit too vigorously than normal, I'm not going to lose sleep over it.

But recognize that introducing oxygen to your beer BEFORE fermentation happens is totally different than AFTER fermentation. It is hard to over-oxygenate before, but not after. But I agree with you that a little bit of aeration during racking isn't something to get overly worried about.

 

[Yooper]

Chris had graphs and everything at the NHC where he talked about this. He did say several times that he was talking only about high gravity beers. The charts and the graphs showed very little difference in the end FG's, except for the higher SG and more oxygenated worts. Those tended to be much lower in FG with the same wort, same yeast, etc. He mentioned that you still don't want to aerate after fermentation- this extra burst of o2 comes in approx 12 hours into the fermentation, still in the lag phase.

He did have the handouts available at the NHC, but I didn't pick them up. Maybe they are on the website?

 

[iQuestor]

Question: I am brewing a fruited sour that requires 2 separate yeast pitches 5 days a part. The first fermentation uses Philly Sour Yeast then 4 days later, you rack to secondary and add the fruit, and pitch a packet of Bell Saison to convert the fruit sugars.

Should I add more oxygen when I pitch the second packet? My thought is that the new yeast would consume the oxygen and there not cause an issue.

What do you think?

 

[BrewZer]

Question: I am brewing a fruited sour that requires 2 separate yeast pitches 5 days a part. The first fermentation uses Philly Sour Yeast then 4 days later, you rack to secondary and add the fruit, and pitch a packet of Bell Saison to convert the fruit sugars.

Should I add more oxygen when I pitch the second packet? My thought is that the new yeast would consume the oxygen and there not cause an issue.

What do you think?

I think there's plenty of dissolved oxygen in the fruit and the cells in the packet have all they need. I wouldn't add any.

 

[deuc224]

I do 4 minutes of oxygen at 1/4 lpm before fermentation and have never ever had a problem fermenting. Ive brewed a westy 12 and an imperial stout that were both in the 12s and nothing went wrong. Gonna do the imperial this weekend and the westy12 next weekend so they can sit in a dark corner at room temp for 9 months.