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Oxygenate at Starter?

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DownHillonWater

DownHillonWater Brews
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It is my understanding that one of the important functions of a starter is to allow yeast to reproduce under aerobic conditions, thus producing lots of healthy cells that can go anaerobically ferment our wort. So.... Does it make sense to actively oxygenate the starter? That is, put a stone attached to a slow oxygen bleed into the starter and let it ferment. One could imagine making a two hole stopper, running an oxygen carrying tube through one hole and putting a bubbler in the second hole. Turn the oxygen on to a low rate, turn on the stir bar, and let it go until the DME is consumed.

Many who read this know a lot more about yeast than I do.... Thoughts?
 
Apparently there are only a few of us HBTers that apply O2 to a starter via a stone.
I use a Williams wand with a .5 micron stone and a flow metered regulator.
But I can't say I've done any analysis wrt growth rate changes, I started doing it because I had the gear for oxygenating wort, so why not use it.
I do get short lag times and healthy fermentations but I could chalk that up to every other aspect of my regimen...

Cheers!
 
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Personally, I think the stir plate alone is enough for making a healthy starter. But, I also don't make a lot of high gravity beers. Maybe for those styles, it would be useful.
 
If you have a stir plate, don't worry about it. If you don't, then infuse some O2 at the beginning of the starter.
 
Perhaps, but it'd take a ridiculous amount.
According to Chris White in Yeast oxygenating wort up to 40ppm did not cause issues.
Considering the target is typically 8-12 ppm that's a huge guardband...

Cheers!
 
AFAIK, there are three of us here on HBT who oxygenate our starters. Day_trippr and I are two, can't recall who the third right now.

Yes, people using stir-plates-only are able to get yeast starters to work. But it always made sense to me that given that we're boiling the starter wort--which drives off oxygen--giving the yeast some O2 to work with at the beginning only made sense. I typically bubble O2 into that starter wort in the flask for 20-30 seconds. Then when that's done, the headspace of the flast has a lot of O2 in it, and the stir plate can help bring that into solution.

I usually pour my starter directly into the wort, no chilling and decanting, and I try to do it when the yeast in the starter is very active, around 14-16 hours. Man, do those fermentations take off! I've had krausen starting to form within 6 hours doing that. Yeah, I'm a pariah that way. Others have expressed concern that the wort from the starter will have off-flavors, but it's never been made clear to me how that's any different than what's going on in the fermenter. And those yeast will clean up anything anyway.

So--do you have oxygenate the starter? No. Is it better? I think so. Will others disagree? Perhaps. Will it keep me up at night? No.

But get a stir plate at the least.
 
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Now I do believe in oxygenating wort prior to pitching my yeast. Doing this provides me with faster start times than when I've chosen to not oxygenate. And I think the resulting finish beer is notably "better". I dont have any triangle test data to show this; its just my personal observation.

But again, still not oxygenating my starters but maybe i'll try it some time and see if I think its worth it.
 
For a starter, yeast will be healthier with a small continuous oxygen source and promote rapid growth. Yeast synthesize unsaturated fatty acids and sterols from oxygen, without O2 Yeast cells do not grow a healthy a cell membrane. A stir plate pushes Co2 out and helps yeast grow. A stir plate keeps yeast suspended also. I would do it with both stir plate and a small continuous O2 for a starter.
 
I used to because I had the equipment to do it however I always do a 2 step starter of 1litre then into a 5liter and found i was going thru the little tanks way to often. I now only aerate the actual beer with it when I pitch. Haven't noticed any difference
 
FWIW, I'm not saying oxygenating starter wort is a replacement for a stir plate--I'm not. I still put my starter on a stir plate.

But I think that's exactly what the linked article is suggesting...and what I thought RM-MN was getting at, until this reply:

What I was questioning with that article is whether either the oxygenation or the stir plate are necessary.

It would seem to me that at least *one* of them *is* necessary to produce healthy yeast in maximal quantities...both oxygenation and the stir plate introduce oxygen, and it seems from reading that linked piece, the stir plate is faster, but not necessarily "better" in the long run.

All this being said, I may be the third person (or perhaps a fourth?) who oxygenates their starters, and then fires up the stir plate. The way I look at it is as a "possibly helpful, not harmful" intervention...only downside is the couple min to sanitize my oxygenation wand, and a few cents of oxygen...
 
What I was questioning with that article is whether either the oxygenation or the stir plate are necessary.

The article is weird. I always am suspect of articles purporting to be authoritative when the author can't even be bothered to edit the article or spell words correctly. Does that make me a grammar-nazi? No. It makes me someone who is discerning of how people choose to present themselves. If you don't care enough to get the details correct in your exposition, you haven't given me much confidence you have the details correct in the content. Your mileage, of course, may vary.

I think that article says little other than White did his experiments without using a stir plate. Beyond that, what did I learn that would either validate my process or cause me to change it? For me, the answer is nothing.

***********

I've read lots of books and articles about how to create a starter. From what I recall, one result of oxygenating is that you'll get healthier yeast. I want yeast with vitality, and optimal conditions are most likely to include that. This includes, of course, allowing yeast access to oxygen in the beginning.

Here's what's said in the YEAST book by White/Zanascheff, and I think this directly contradicts what's in the article:

Page 134: "There are several ways to add oxygen: intermittent shaking, continuous shaking, a stir plate, pure oxygen, or an air pump with a sterile filter. If you have a stir plate, that is perhaps the most effective method. A stir plate provides good gas exchange, keeps the yeast in suspension and drives off carbon dioxide, all of which increase yeast growth (around two to three times as much yeast as a nonstirred starter) and improve yeast health." [emphasis mine]

So, there it is. White/Zanascheff say a stirred starter produce more yeast than a nonstirred starter. @RM-MN, that pretty much directly addresses your question, I think. A good question, and I think that those two guys are probably more...believable, perhaps...than the author of that article referenced above.
 
I think the OP specifically asked "So.... Does it make sense to actively oxygenate the starter?". And I think most of us have agreed that it does make sense to oxygenate a starter in some way. But, the debated topic has been about oxygenating starter wort with a direct O2 source prior to stirring -vs- just letting the stir action introduce O2 naturally.

But the OP also specifically asks if "active oxygenation" should be done while on a stirplate with a steady, controlled supply of O2...
That is, put a stone attached to a slow oxygen bleed into the starter and let it ferment. One could imagine making a two hole stopper, running an oxygen carrying tube through one hole and putting a bubbler in the second hole. Turn the oxygen on to a low rate, turn on the stir bar, and let it go until the DME is consumed.

To that I'd say; in a very controlled setting this could produce the ideal conditions for optimal yeast growth and health. However, I lean towards the K.I.S.S. principal when possible and I dont think the additional complexity of this would have enough of a return to make it worthwhile. Certainly not as a home brewer anyway... So, the process makes sense but doesnt seem practical for the home brewer IMO.
 
There is zero evidence to support dosing a starter with pure o2 before using a stir plate makes a better beer. Better means fewer yeast derived flaws here. However, it can create more yeast growth in the starter. More growth than yeast calculators estimate.

Infusing pure O2 into a stir plate starter isn't necessary for a healthy fermentation. It's a possible source of infection that isn't worth the remote risk.
 
Perhaps, but it'd take a ridiculous amount.
According to Chris White in Yeast oxygenating wort up to 40ppm did not cause issues.
Considering the target is typically 8-12 ppm that's a huge guardband...

Cheers!

The same book says higher than necessary DO increases fusels. This is a lot less than 40ppm. Conventional wisdom derived from brewing science agrees. CW's statements are not always completely consistent. Yeast the microbe isn't completely consistent either. In terms of fusels, yeast is highly variable under the same conditions.

High DO ferments have been studied and they used about 20ppm for the high end. The higher DO beers fermented a little faster and had a slightly worse sensory perception than the lower DO beers. They did not measure fusels. My body measures fusels very well. Too much O2 in a 3787 trippel made a punishing fusel beer for me once. Never again!
 
There is zero evidence to support dosing a starter with pure o2 before using a stir plate makes a better beer. Better means fewer yeast derived flaws here. However, it can create more yeast growth in the starter. More growth than yeast calculators estimate.

And....there isn't any evidence it doesn't. We may have to agree to disagree here. I believe (you may or may not) that the faster I get a good, vigorous fermentation going, the better. The more oxygen the yeast have to support them in the starter, the better the yeast will be, and the better will be the fermentation.

My beers actually taste really good. I get feedback to that effect from lots of people, who will have more than one.

Here's an interesting question: Have you ever done it? I mean, have you ever oxygenated your starter wort? And seen what develops?

Infusing pure O2 into a stir plate starter isn't necessary for a healthy fermentation. It's a possible source of infection that isn't worth the remote risk.

Everything is a possible source of infection. Just like oxygenating the wort after brewing. I boil RO water and sterilize the oxygenation wand in that water, and spray the heck out of the wand with Star-San. Saying something is "possible" sounds like you're reaching for some reason to believe it's unimportant.

I just finished putting my brew stuff away. Yeast pitched at 3:30pm this afternoon. WLP 940, made in a starter where I added a pinch of yeast nutrient and I oxygenated the starter wort.

I'll report back later when I see airlock activity and the beginning of a krausen.
 
I'm not going to multi quote @mongoose33 and destroy the entire post line by line. It was a good enthusiastic post that attempts to defend his unnecessary use of pure O2 in a stir plate starter.

Faster fermentation is a claimed benefit and he is willing to report how quickly his batch takes off by looking for an airlock bubble. The first airlock bubble is an indicator of fermentation happening several hours before the bubble occurred. Different fermenters have different head spaces. Not all air locks are the same. So observations of early bubbles is generally not a fair comparison outside your brew house.

That said, my regular stir plate starters are typically pitched at 4-6pm and the fermenters are typically bubbling sometime around 12pm-3pm the next day using a very long blow off tube. They would bubble a lot sooner with a regular airlock.

I'm sure you and the people that like to drink your beer think it tastes good. It probably does. No, I have not infused pure O2 into a stir plate starter because my beers have never exhibited yeast derived defects that might be cured with your redundant O2 starter method.

Cavalierly dismissing the unnecessary O2 starter infusion as a possible source of infection is something a self proclaimed scientist should rethink. Propagation of unwanted microbes in a starter never ends well.
 
Since there are a few O2 infusion prior to stir plate enthusiasts in this thread and some of them point to excerpts from the excellent book Yeast to validate their method, I encourage them to show us where the book Yeast says this method is better than a standard stir plate method.
 
I'm not going to multi quote @mongoose33 and destroy the entire post line by line. It was a good enthusiastic post that attempts to defend his unnecessary use of pure O2 in a stir plate starter.

Well, as I said, we'll have to agree to disagree. Without any evidence other than your enthusiastic attempts to denigrate a reasonable approach, we'll have to assume you're just guessing.

But that's OK.

Faster fermentation is a claimed benefit and he is willing to report how quickly his batch takes off by looking for an airlock bubble. The first airlock bubble is an indicator of fermentation happening several hours before the bubble occurred. Different fermenters have different head spaces. Not all air locks are the same. So observations of early bubbles is generally not a fair comparison outside your brew house.

How ironic. On the one hand, you argue that oxygenating starter wort is a potential source of infection, which it is. But you don't see any benefit to fast fermenation takeoffs which, if there are bad microbes in the beer, can outcompete them.

That's....interesting. My son is a microbiologist and he's the one who explained this to me. I choose to believe him, and not so much, you.

That said, my regular stir plate starters are typically pitched at 4-6pm and the fermenters are typically bubbling sometime around 12pm-3pm the next day using a very long blow off tube. They would bubble a lot sooner with a regular airlock.

Sounds like the yeast are stressed. Otherwise, they wouldn't take nearly 18-20 hours to take off. Or, perhaps they'd be more inclined to GO if you'd oxygenated the starter.

I'm sure you and the people that like to drink your beer think it tastes good. It probably does. No, I have not infused pure O2 into a stir plate starter because my beers have never exhibited yeast derived defects that might be cured with your redundant O2 starter method.

OK, thank you. It *is* good. And I don't just rely on my own evaluation of it, though there's nothing inherently wrong with that. I rely on what others tell me as well, and I use the "do they have a second one" indicator of whether someone likes my beer or not.

Now, here's an interesting thing. Just because you can't detect yeast-derived defects doesn't mean they're not there. It might just mean that you can't detect them. BTW, this is the kind of thing a scientist looks for--an alternative explanation for results. Perhaps you just can't taste the defects.

Cavalierly dismissing the unnecessary O2 starter infusion as a possible source of infection is something a self proclaimed scientist should rethink. Propagation of unwanted microbes in a starter never ends well.

There are a million possible sources of infection. Cavalierly assuming that I'm unaware of or dismissing the possibility of contamination would presume that I am unable to manage my process to prevent that.

I get that you don't want to do this. It's the same reaction of people to low-oxygen brewing, or to BIAB. Once they have their process down, they don't want to hear there may be a better way. So they'll denigrate the new method even though they have no experience with it.

I am a scientist. If one is trained well as one--I'd like to think I am--then the name of the game is to look for reasons why one is wrong, not why one is right. It's what science is. You see, we're both looking for the same thing, evidence that oxygenating starter wort is either useless or even harmful. But I'm doing it to test my theory; it appears you're doing it because you're threatened by it.
 
oh boy... Cant believe such a heated conversation has been incited.. @Steve King : Please do continuous oxygenation in your starter if you think its something you want to try. In the end, you do what works for you to make good beer. These topics are "splitting hairs" when it comes to making good beer. Enjoy and RDWHAHB!
 
I have always been of the opinion that I should not weigh in on a debate (or process) until I am properly informed to do so. Being this will remain my position, I have had very predictable results with WLP 850 Copenhagen yeast which has become my go to lager strain. I have used it frequently enough to be able to tell subtle nuances in the starter itself and in the fermentation.

On my next starter with 850, I plan to oxygenate the starter wort before using my stir plate as normal. Following the oxygenation suggestions provided by @mongoose33 and @day_trippr, I'll also do a direct pitch of the starter w/o crashing and decanting so my process will follow closely.

What can it hurt to try this? If I can shave off even 4 hours until the yeast launches, I have done a good thing. I use a medical oxygen tank for brewing, so this is certainly no biggie to try. Afterwards, I'll feel qualified to weigh in and say whether this works for me in my process....or not. Until I am at that point, anything I say about this process working or not is unfounded and frankly doesn't count.

After I try oxygenating a starter, I'll post my results on this thread. Thank you, @mongoose33, for taking your time to post your findings.
 
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