Can aeration before pitch cause oxidation?

[MrBJones]

Before pitching, I aerate by putting the capped carboy across my legs as I sit, and then rocking it repeatedly. It gets churned up pretty good, even foamy. Could that lead to oxidation down the line? I don't think I've had any, but then most of my brews are gone within a month or so.
Thanks

 

[Barbarossa]

No. The yeast will take care of it. You actually need to oxygenate the wort to make the yeast happy.

 

[MrBJones]

No. The yeast will take care of it. You actually need to oxygenate the wort to make the yeast happy.

Is it possible to overdo it?

 

[bionicbelly]

Is it possible to overdo it?

I think you can by adding pure oxygen with an aeration stone, but not with the method you are using.

 

[Brew_Dude41]

I am sure someone from team LODO will tell you that you are impacting your final product in some manner from oxidation throughout your process.
Personally, that always worked well for before I got a diffusion stone and an O2 tank. I never had issues, and I could not perceive any off flavors. (Doesn't mean they weren't there-I just never noticed)

 

[MaxStout]

I find it hard to believe that oxygenating the wort, then pitching the yeast immediately after is more detrimental than if I reversed the order of two functions. Maybe somebody has a comparison with measurements to support the idea.

 

[Broothru]

I am sure someone from team LODO will tell you that you are impacting your final product in some manner from oxidation throughout your process.
Personally, that always worked well for before I got a diffusion stone and an O2 tank. I never had issues, and I could not perceive any off flavors. (Doesn't mean they weren't there-I just never noticed)

Team LODO here. I oxygenate every brew. The yeast need it for healthy and robust propagation. In my experience it's hard to overdo it since the yeast will consume virtually all the D.O. present in the wort during the first hour or so of the adaptive phase.

I do what @MaxStout hinted at, by pitching the yeast first and then hitting the wort with O2, through a sintered stone, at 4 liters/minute flow rate for 3~4 mins. Then cap. As long as you're not adding O2 at a rate that causes bursting bubbles on the surface, the amount of gaseous O2 in the headspace will be minimized, and the dissolved oxygen will be consumed by the yeast.

Closed (or pressurized) fermentation, trub dump in lieu of secondary, primary to completion with spunding, transfer under positive pressure to a purged serving keg. Ain't no stinking oxidation in my process.

 

[hotbeer]

I'd expect oxidation to be more from bad techniques you use when racking your beer in preparation from bottling or kegging. Probably some from poor seals on the fermenter letting CO2 out and air in as ambient temp and atmospheric pressure changes.

 

[day_trippr]

Well...left to its own devices, oxygen that dissolves into beer is bound to oxidize. And if one used pure O2 to bring wort cooled to pitching temperature to the 8-12 ppm most yeast manufacturers recommend - but never actually pitched the yeast - you can bet that wort would suffer for every minute it was left on its on.

Otoh, pitching then adding O2 to the same level ensures the yeast get what they need for sterol production while only exposing the wort to the minimum. When I still had an O2 meter the first time I watched how fast the O2 dropped from 12 ppm to literally below the instrument's threshold I was stunned and had to double-check that zero reading to believe it.

Cheers!

 

[ncbrewer]

When I still had an O2 meter the first time I watched how fast the O2 dropped from 12 ppm to literally below the instrument's threshold I was stunned and had to double-check that zero reading to believe it.

Don't leave us in suspense - how fast was it?

 

[day_trippr]

Lol! Sorry. I checked every 20 minutes and at 60 minutes it was undetectable with the borrowed mw600 I was using.
That was in ~5.5 gallons. I was impressed. And convinced I didn't actually need an O2 meter of my own

Cheers!

 

[Bilsch]

It depends on a lot of factors but pitch temperature and yeast health mostly. Most Lodo guys are oxygenating first and then pitching. As long at your yeast is in good condition they will scavenge up the oxygen before oxidative damage can be done. But yea, healthy yeast are fast.

 

[MaxStout]

It depends on a lot of factors but pitch temperature and yeast health mostly. Most Lodo guys are oxygenating first and then pitching. As long at your yeast is in good condition they will scavenge up the oxygen before oxidative damage can be done.

That's my method. Oxygenate with a stone, IMMEDIATELY pitch, then button up the fermenter.

 

[Bilsch]

That's my method. Oxygenate with a stone, IMMEDIATELY pitch, then button up the fermenter.

This is de rigueur in the Lodo world. Although most check with do meters to be sure.

 

[ncbrewer]

I understand from the forums and many I know that lots of brewers pitch dry yeast on foamy wort. It seems like there could be some oxidation going on there while the yeast is still suspended on the foam.

 

[Bilsch]

I understand from the forums and many I know that lots of brewers pitch dry yeast on foamy wort. It seems like there could be some oxidation going on there while the yeast is still suspended on the foam.

IMO Those who aim to make the absolute best beer should avoid dry yeast.

 

[PCABrewing]

I understand from the forums and many I know that lots of brewers pitch dry yeast on foamy wort. It seems like there could be some oxidation going on there while the yeast is still suspended on the foam.

My understanding is that the biggest risk is hot-side oxidation, I.E. introducing oxygen to the wort above pitching temperature.
That can happen during transfer from kettle to the fermenter due to splashing or by using the stone on wort that hasn't been chilled enough.
I always chill to near pitch temp. before transfer from the kettle.

 

[AlexKay]

IMO Those who aim to make the absolute best beer should avoid dry yeast.

Um … ok, I guess? I’ll go the other way: dry yeast is so good, and there are good options for enough styles, that I’m not really sure why people use liquid yeast anymore.

 

[BrewnWKopperKat]

@AlexKay, @Bilsch makes a point worth listening to within it's context.

There are many here who want to brew the absolute best beer. There are others here who want to make enjoyable beer as a hobby.

For many, a specific strain of liquid yeast is that "secret ingredient" that moves a good beer to a great beer. For others it's a specific brand of base malt.

 

[AlexKay]

For many, a specific strain of liquid yeast is that "secret ingredient" that moves a good beer to a great beer. For others it's a specific brand of base malt.
[/QUOTE]

Well, as somebody who is very particular about maltsters (usually not for base malts, but still) I hear your point: I wouldn’t try to make a Grodziskie without Sugar Creek malt, for instance.

But I do think you can make a great lager with 34/70, for instance. Maybe not exactly the subtype of lager you’re looking for, but a great lager nonetheless. Ditto ales with US-05. And some others.

 

[MaxStout]

I was a long-time liquid yeast brewer, until my nearby (4 miles away!) LHBS closed in 2019 and then the pandemic hit. I didn't want to drive across the metro to MW or NB for a $7 purchase (and for a while they didn't allow walk-in customers). So internet was my option, and I DO NOT trust getting liquid yeast by mail. I'll order most anything else online, but not yeast. I live in MN - hot in the summer, freezing-ass cold in the winter.

So I started brewing with dry. I wanted to see what I could do within those bounds, and a brewer can make good, if not spectacular, beers. While I've brewed some good beers with dry, and I am quite content with them, I do miss the ability to really dial in to a style with a liquid strain. I can't quite get the same result for say, a Kolsch or English bitter with dry. I can get close enough for government work, but that's it.

Now that things are starting to open up, I might venture to MW and get back to liquid strains and starters and hitting the style bullseye. Besides, I have a MW gift certificate burning a hole in my pocket.

/Gone a bit OT here.
//Don't want to start a liquid vs. dry argument. @Bilsch has a point.
///I now return you to your regularly scheduled programming.

 

[Bilsch]

Um … ok, I guess? I’ll go the other way: dry yeast is so good, and there are good options for enough styles, that I’m not really sure why people use liquid yeast anymore.

Because the lag time on heathy liquid yeast is much shorter than the best dry. The faster your yeast goes to work the better the final product. It’s just that simple.

 

[BrewnWKopperKat]

But I do think you can make a great lager with 34/70, for instance. Maybe not exactly the subtype of lager you’re looking for, but a great lager nonetheless. Ditto ales with US-05. And some others.

I agree.


And, as @MaxStout said,

/Gone a bit OT here.
//Don't want to start a liquid vs. dry argument. @Bilsch has a point.
///I now return you to your regularly scheduled programming.​

 

[DarrellQ]

Um … ok, I guess? I’ll go the other way: dry yeast is so good, and there are good options for enough styles, that I’m not really sure why people use liquid yeast anymore.

Because of Omega Lutra OYL071. Pretty incredible stuff that is happy anywhere between 68-95 degrees. Even makes decent pseudo-lager at these temps.

 

[tracer bullet]

Because the lag time on heathy liquid yeast is much shorter than the best dry. The faster your yeast goes to work the better the final product. It’s just that simple.

I hadn't ever thought of this, and it's a really interesting point. I'd be curious how long it takes dry to aborb the O2 and how noticeable it is. My dry experience is that it always takes off but does take longer. I suppose if I pay more attention I could see for myself how much longer the O2 sits there unused. As for the effect... Would be a lot harder to gauge since an apples / apples comparison wouldn't be easy. Hmm.

Off topic but maybe loosely related regarding dry yeast use -

I was a long-time liquid yeast brewer, until my nearby (4 miles away!) LHBS closed in 2019 and then the pandemic hit. I didn't want to drive across the metro to MW or NB for a $7 purchase (and for a while they didn't allow walk-in customers). So internet was my option, and I DO NOT trust getting liquid yeast by mail. I'll order most anything else online, but not yeast. I live in MN - hot in the summer, freezing-ass cold in the winter.

Funny how our experiences consistently overlap. And I think we established we live in the same part of town. I too miss Brew & Grow, was going to Kevin's store for decades all the way back to when they were on University near Northtown Mall. I've found that if you go to MW during the middle of the day it's about 20 minutes since traffic is always light and cruising pretty fast. Anyhow...

I'm a Rite-Brew fan but also had a bad batch after I got lazy and used some yeast that had been sitting around warm last summer. SpeeDee is usually overnight but that time they messed up and it sat in Saint Cloud for a week. So I now do a combo of MW if I want a specific liquid yeast for an experiment and still RB but with the dry option when I just want to make beer. This time of year it's probably pretty safe to get liquid yeast via the internet again, but only for a while.

 

[Broothru]

This is de rigueur in the Lodo world. Although most check with do meters to be sure.

I wonder if there'd be any advantage to pitching yeast while simultaneously adding O2? Maybe even oxygenating under a slight head of pressure <5 psig to keep oxygen in solution for the first hour until O2 is consumed?

I know... measure with micrometer, cut with axe.

 

[TBA]

Since we are off topic.. If you pitch dry yeast but harvest (top crop or slurry) is the subsequent pitch considered dry or liquid? When I have repitched a dry yeast the lag time has been extremely short.

 

[Bassman2003]

I think you can consider dry yeast liquid if you re-pitch, but there are concerns about the initial damage in making the yeast dry that might permanently impact going forward. I do not know for sure, just relaying discussions. As with many things, convenience often comes with tradeoffs.

About the DO pickup after chilling, I dd a little no-chill type of test by boiling some water, chilling it to 100F then putting it in a fridge. I monitored the rate of temperature change and DO pickup. It took about 13 hours to chill from100F to 50F and on average, the water picked up .22 ppm of DO per hour. So the DO pickup risk is relatively low since there is no movement and the temps are low-ish.

DO pickup is less at lower temperatures. DO does more damage at higher temperatures. That is why so many focus on limiting O2 on the hot side. There is still debate about what to do at pitching. The problem is around expending any leftover suflites (if you use sulfites) as they suck up any O2 you add.

 

[BrewnWKopperKat]

If you pitch dry yeast but harvest (top crop or slurry) is the subsequent pitch considered dry or liquid?

Liquid.

Further off-topic (yet still talking about home brewing): A couple of years ago, there were some topics over in AHA forums that discussed the perceived differences between the 1st pitch of dry yeast strains and the follow-on pitches (using liquid yeast techniques). I may have some links in my notes. If you are interested in looking into this further, let me know and I can see if I can find the links in my notes.

 

[TBA]

@BrewnWKopperKat if it isn’t much trouble please post the links. I have heard about changes over multiple repitches but would like to read more about it.