aerating DURING fermentation?

[bottlebomber]

New brewer here. I've been researching brewing large beers, and have run into talk about big beer and big yeast such as wlp099. Here's what I don't understand- typically you want beer to NOT oxygenate after pitching right? It produces cardboard flavors or something? But then for these big beers, even at the white labs website it says to oxygenate during fermentation. How is this different?

 

[Brewstress]

You might be confusing hot side aeration of the sparge with aeration of the wort after cooling to pitching temperature. The wort will not oxidize at room temperature, but will at higher temps like mash temps. However, aeration of the wort before pitching allows the yeast to get to a nice colony size before they start to convert the sugars in the wort into alcohol which can only be done once they have consumed all of the oxygen out of their environment. I used to just pour the cooled wort from a counter top into the fermentor sitting on the floor to aerate, but now I use an air stone with an air pump and an in-line filter. Hope this helps.

 

[Hammy71]

Yes, you aerate before fermentation. On high gravity beers it is often useful to aerate the beer again, (usually within 12-24 hours after pitching). The extra aeration will help the yeast to propagate to the numbers you need for a 'big brew'. The yeast will absorb the oxygen during their growth period, so no harm to the beer. AFTER fermentation, when the yeast aren't growing and therefore not using the oxygen, is definitely a no-no.

 

[bottlebomber]

AFTER fermentation, when the yeast aren't growing and therefore not using the oxygen, is definitely a no-no.

Right, I know to aerate before you pitch. Not that much of a noob what im talking about though is aerating WHILE the fermentation is taking place. If you look at the notes of white labs wlp099 it says to aerate during the first 5 days of fermentation. And the big beer makers on here are talking about adding yeast throughout the ferm and aerating after additions. I was just wondering if anyone knew why this was possible but aerating other times is not advised

 

[Wakadaka]

Right, I know to aerate before you pitch. Not that much of a noob what im talking about though is aerating WHILE the fermentation is taking place. If you look at the notes of white labs wlp099 it says to aerate during the first 5 days of fermentation. And the big beer makers on here are talking about adding yeast throughout the ferm and aerating after additions. I was just wondering if anyone knew why this was possible but aerating other times is not advised

The yeast probably eat up all of the oxygen so that none is left to oxidize the beer. I think during the first 5 days of fermentation is a rough guideline, that shouldn't necessarily be followed. Seems like the better time to do it would be when you start seeing activity.

There is only a set amount of oxygen that you can get into wort, and re-aerating will just help you to get even more oxygen in for the yeast to consume.

Or at least a couple semesters of chemistry and biology lead me to believe that is the case. I haven't brewed anything too big yet so I can't say from experience

 

[BrewKnurd]

Right, I know to aerate before you pitch. Not that much of a noob what im talking about though is aerating WHILE the fermentation is taking place. If you look at the notes of white labs wlp099 it says to aerate during the first 5 days of fermentation. And the big beer makers on here are talking about adding yeast throughout the ferm and aerating after additions. I was just wondering if anyone knew why this was possible but aerating other times is not advised

I thought he explained it pretty well.... yeast need oxygen to propagate. They use it to make sterols which they use for building cell walls which allows them to reporoduce and grow big and strong. So if your yeast are propagating, they will take up the oxygen and you won't have problems. If your yeast are NOT propagating (especially after fermentation is complete and they've started settling out), the O2 can stick around and oxidize your beer.

 

[bottlebomber]

I thought he explained it pretty well.... yeast need oxygen to propagate. They use it to make sterols which they use for building cell walls which allows them to reporoduce and grow big and strong. So if your yeast are propagating, they will take up the oxygen and you won't have problems. If your yeast are NOT propagating (especially after fermentation is complete and they've started settling out), the O2 can stick around and oxidize your beer.

Ok I think I understand now... I was under the impression oxygenation "off flavors" were something that happens immediately or very quickly. So as long as the yeast have enough "work" to do, they will use up any oxygen in the solution. This makes sense now

 

[SnallygasterBrewery]

Depends on the strain in addition to other things, too. Some reach FG faster than others. It's a function of pH, temperature, SG, pitching rates, aeration, etc. All the oxygen is consumed by yeast very very quickly, so reintroducing some to help spur more growth while they're just getting started can really help them out and reduce lag to ensure a good fermentation. Think of a starter using a stir plate with constant aeration versus one just shaken now-and-again. Oxygen does play a role in reintroducing off-flavors like you though. Diacetyl, for example, may be present in beer in a big way if the yeast was crashed or not given ample time to clean up, but may stay low-key unless oxygen pickup increases its presence. Anyway, you get the gist.

 

[Revvy]

New brewer here. I've been researching brewing large beers, and have run into talk about big beer and big yeast such as wlp099. Here's what I don't understand- typically you want beer to NOT oxygenate after pitching right? It produces cardboard flavors or something? But then for these big beers, even at the white labs website it says to oxygenate during fermentation. How is this different?

Actually it's the first 12 hours and that's for high grav beers only.
Here's the info from an older post of mine;

It caused quite a stir when it first came out a couple years back at a conference Chris White of Whitelabs presented that info about adding 02 within 12 hours of a big beer. IIRC there was some pretty heated arguments on here. But yes it is recommend for big beers that you give it a second period of aeration within the first 12 hours after yeast pitch. Before enough fermentation has happened to have to worry about oxydation. !2 hours and for beers above 1.080 I think.

edit I found some of the initial info from way back then. It was Chris White of Whitelabs not the guy from Wyyeast

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...

It was a good discussion here;

https://www.homebrewtalk.com/f13/adding-oxygen-during-fermentation-71456/

I'm all for a post yeast pitch blast of O2....but BEFORE it begins to turn into real beer......within the first 12 hours...but with already a 20 point drop in gravity, I still maintain that you don't want too much o2 exposure now...

Flyguy gives a good elaboration on it...

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.

 

[bottlebomber]

Thanks that's a lot of great info

 

[bourgeoisbee]

You've got it right about within the first 12 hours or so, but FYI, you'll find most people don't like the flavor of wlp099 as the first/only yeast pitched. Try pitching wlp001 (if going for an American style, otherwise a style appropriate yeast) with a big starter first, and then letting wlp099 do the rest of the work. Wine yeast is an option then too, but check with how far down it will go if you don't want a really dry beer.

 

[bottlebomber]

You've got it right about within the first 12 hours or so, but FYI, you'll find most people don't like the flavor of wlp099 as the first/only yeast pitched. Try pitching wlp001 (if going for an American style, otherwise a style appropriate yeast) with a big starter first, and then letting wlp099 do the rest of the work. Wine yeast is an option then too, but check with how far down it will go if you don't want a really dry beer.

To some extent you can control dryness with mash temp/duration by extracting unfermentables is that correct?

 

[SnallygasterBrewery]

Higher mash temps encourage dextrinous wort (so yeah, you'll be able to ferment to a greater degree by mashing on the lower end for longer)

 

[wooby111]

I apologize if I missed it, but it seemed that nobody really addressed the main question here, which was... Is it safe to continue pushing air/oxygen into wort after 2,3 or even 5 days of pitching wlp-099, like the website suggests? I just did a huge barleywine that started at 1.108 and upped it to 1.150 after all the dextrose additions. 1056 took it down to 1.034 and I pitched the 099 decanted 2L starter after that just 2 days ago, and it's been SLOW (about a bubble every 8 seconds). I pumped oxygen in the last 2 nights for aout 10 minutes per. I'm nervous I could give it more oxygen that it needs to finish.

 

[bottlebomber]

I apologize if I missed it, but it seemed that nobody really addressed the main question here, which was... Is it safe to continue pushing air/oxygen into wort after 2,3 or even 5 days of pitching wlp-099, like the website suggests? I just did a huge barleywine that started at 1.108 and upped it to 1.150 after all the dextrose additions. 1056 took it down to 1.034 and I pitched the 099 decanted 2L starter after that just 2 days ago, and it's been SLOW (about a bubble every 8 seconds). I pumped oxygen in the last 2 nights for aout 10 minutes per. I'm nervous I could give it more oxygen that it needs to finish.

Don't do it. 099 is a slow mover for that last leg of attenuation. I know they tell you to use oxygen, but it's a good idea to avoid doing this. The best way I've found it to incorporate the olive oil method into the 099 starter so that you don't need to increase oxygen. I've had excellent results with this.

 

[wooby111]

Don't do it. 099 is a slow mover for that last leg of attenuation. I know they tell you to use oxygen, but it's a good idea to avoid doing this. The best way I've found it to incorporate the olive oil method into the 099 starter so that you don't need to increase oxygen. I've had excellent results with this.

Well, I guess at this point/batch, the best I can do is STOP doing it, and hope for the best over the next 2 weeks. Lesson learned. Thanks.