Let's talk about Oxygen.

[GrowleyMonster]

So far, I have not oxygenated any of my beers. Seems to work okay. Using US-05 yeast either pitched fresh on new wort, or left in the trub and the next batch poured directly on it. I have even gone so far as to purge the fermenter with C02, thinking it was a good idea because Oxygen is the enemy of beer, right? I did not know that oxygen is needed by the yeast. Pitching fresh yeast gives me a sluggish start without oxygen but eventually it gets the job done. Leaving the trub for the next batch of wort usually gives me obvious fermentation in just a few hours.

So, SHOULD I be oxygenating? How much is too much? How much is too little? I gather that this should be done before fermentation begins, and I understand why late oxygenation is bad. What happens with too little, or too much oxygen? I gather that many brewers just pour wort in a fermenter already filled with ambient air, so is unfiltered air bubbled into the fermenter really a bad thing? How about just mouth blowing with a piece of tubing? I would much prefer not to buy anything, especially recurring costs like disposable oxygen cylinders or disposable filters. I keep telling GF I am brewing to save money and she is like, "RIIIIIIIiiiiiiiight...." as she tiptoes between all the BMB's and corny kegs and various boxes of hoses and equipment in the dining room.

 

[kevin58]

Don't be too concerned about a "sluggish"start. It is part of the yeast life cycle as they build up and prepare to reproduce. It is this reproduction period that we can visually see as krausen building up and activity in the airlock. The yeast are very much at work even before you can observe this phase... and after.

Yes, yeast need oxygen as part of their food supply. How much is a matter of debate. If you do oxygenate or aerate do it just before pitching yeast.

As for the money saving aspect... don't even go there as a means of justifying homebrewing to your significant other. It's a hobby.

 

[Jag75]

I actually never oxygenate my wort when pitching dry yeast . Never had an issue . I do when using liquid yeast though. I just sprinkle dry yeast on top of the wort .

 

[kh54s10]

Dry yeast is coated with nutrients and such that oxygenation is not necessary. If you are pitching onto a fresh slurry of harvested yeast it is probably ok to skip the oxygenation. If it is older I would oxygenate. For liquid yeasts I would always oxygenate. The yeast need it to reproduce. How much depends on how you are getting the oxygen in there. Shaking the fermenter = at least 5 minutes. Air pump = maybe 30 minutes. Oxygen cylinder = seconds (I don't know how long).

Shaking or air pump is said to be only capable of 8 ppm. Million or billion? I forget. Oxygen can get you above 10.

There was a recent thread on US-05 being a slow starter. A lot said it was. I never noticed it being much different than any other yeast.

 

[Kirkwooder]

I don't use an air pump or bottled o2. I do rack through a screened funnel slowly and make sure there is plenty of agitation while doing so. Then I shake to agitate even more. Takes me roughly 1/2 hour more on a 5 hour brew session and the fermentation's seem to start better/faster than if I don't. No need for more equipment that I really don't have room or funds for.

Just my $.02

 

[balrog]

one other point about your anecdotal evidence, is that pitching with a pack of yeast gives you a certain amount, which will have to multiply to have a happy yeast cell concentration in the wort. Pitching on the trub of a prior batch starts with the yeast already multiplied and thereby reduces "lag time" as they do not need to multiply.

Nothing to do with oxygen.

 

[GrowleyMonster]

Thanks for all the great replies. I guess I will just keep brewing without oxygenation, using either US-05 or fresh trub, like I have been doing. I will stop purging the fermenter before racking into it, and maybe I might give it a good shake before pitching dry yeast. But I gather that having too much oxygen is probably not going to happen, as long as it is introduced before pitching yeast, and that too little oxygen is not really a thing except with either old trub or slurry, or liquid yeast. Am I right? I am pretty meticulous about avoiding air exposure after pitching, already. I purge my kegs, secondaries, even hoses, with CO2. I was purging primary fermenters too, but I guess that isn't needed.

 

[kh54s10]

Even with dry yeast, oxygenating will not hurt anything. But you are right, eliminating oxygen after the yeast have begun fermentation is important. Many go to great lengths to eliminate oxygen at every phase except when pitching the yeast.

 

[Kenmoron]

You can actually continue to oxygenate into fermentation on really big beers (>1.080) in order to increase yeast health and attenuation. This can be done as long as you are less than 50% to your goal FG. This information was given to me by a friend that went to a yeast lab boot camp recently. For example, if your OG is 1.100 and anticipated FG is 1.020 you can continue to oxygenate during fermentation as long as you are still above 1.060.

 

[FswBG]

You can actually continue to oxygenate into fermentation on really big beers (>1.080) in order to increase yeast health and attenuation. This can be done as long as you are less than 50% to your goal FG. This information was given to me by a friend that went to a yeast lab boot camp recently. For example, if your OG is 1.100 and anticipated FG is 1.020 you can continue to oxygenate during fermentation as long as you are still above 1.060.

That's good to know. I have always heard of hitting the wort with O2 again on big beers 12-18 hrs later, but have always been too nervous to try.

It's not too often that I go for high gravity, but I will have to give this a go on my next RIS. Cheers.

 

[Vale71]

You can actually continue to oxygenate into fermentation on really big beers (>1.080) in order to increase yeast health and attenuation. This can be done as long as you are less than 50% to your goal FG. This information was given to me by a friend that went to a yeast lab boot camp recently. For example, if your OG is 1.100 and anticipated FG is 1.020 you can continue to oxygenate during fermentation as long as you are still above 1.060.

That's utter nonsense. If you keep oxygenating that long you'll have severely oxidized beer straight out of the fermenter, might as well dump it right away.

 

[Vale71]

That's good to know.

No it isn't. This is total misinformation and must be disregarded.

 

[kh54s10]

That's utter nonsense. If you keep oxygenating that long you'll have severely oxidized beer straight out of the fermenter, might as well dump it right away.

He quoted a friend who got the information from someone from a yeast lab. Where does you information come from that this is wrong? Not saying that the third hand information might not be in error...

 

[Kenmoron]

That's utter nonsense. If you keep oxygenating that long you'll have severely oxidized beer straight out of the fermenter, might as well dump it right away.

@Vale71 Can you tell what information/resources you have to back up your claim? My friend who told me about the oxygenation until 50% predicted gravity got it from doing a yeast bootcamp at Whitelabs this past summer. He brought back fairly extensive notes and provided our homebrew club with a presentation on a bunch of findings/information/myths/etc.

 

[Day-Day]

I don't like to wonder if there was something that I could have done or should have done to improve my beer... so I do everything I can to provide a good envrionment for healthy fermentation... that includes hitting the wort with pure oxygen prior to pitching the yeast.

Although, my motive is to make the absolute best beer possible...not to save time, money, or space... other peoples' motives might be different than mine... and they may choose to do things differently and or leave certain things out... that's their choice... it's their hobby.

Is oxygenating the wort absolutely necessary for fermenation... no... the beer will ferment either way. Does it improve fermenatation ... I've been told it does when added in the proper amounts.

 

[hottpeper13]

You know the guys that do this extra oxygenating are most likely using meters and equipment we modest homebrewers can only dream of, conicals, Tilt hydros, ect. So I brew beers north of 1.100 and never do a second hit and get 1.016-1.020 FG if that's what the style needs. Since most need blow off tubes, I'd say a vigorous fermentation was accomplished. I do hit those with 5 min of O2 at 1/8 L per min.

 

[kh54s10]

You know the guys that do this extra oxygenating are most likely using meters and equipment we modest homebrewers can only dream of, conicals, Tilt hydros, ect. So I brew beers north of 1.100 and never do a second hit and get 1.016-1.020 FG if that's what the style needs. Since most need blow off tubes, I'd say a vigorous fermentation was accomplished. I do hit those with 5 min of O2 at 1/8 L per min.

I don't think that most who do big beers and do a second oxygenation have any super equipment. Probably one of those red tanks, a regulator and a wand with an aeration stone. Most do the second addition at 24 hours, so unless someone takes a gravity reading just before that, who knows how far the gravity has dropped?

1.100, IMO, is high but not high enough to require the second hit. I think the ones that are getting the second hit are quite a bit higher than that.

 

[Vale71]

@Vale71 Can you tell what information/resources you have to back up your claim? My friend who told me about the oxygenation until 50% predicted gravity got it from doing a yeast bootcamp at Whitelabs this past summer. He brought back fairly extensive notes and provided our homebrew club with a presentation on a bunch of findings/information/myths/etc.

Just look in pretty much every basic brewing technology text, be it Kunze or Narziß or Bamforth or whatever.

I'm really surpised that Whitelabs would hand out such bad advice, on the other hand they're in the business of culturing yeast and not making beer so they're not the first source I would turn to for advice on the latter topic.

 

[kh54s10]

You can actually continue to oxygenate into fermentation on really big beers (>1.080) in order to increase yeast health and attenuation. This can be done as long as you are less than 50% to your goal FG. This information was given to me by a friend that went to a yeast lab boot camp recently. For example, if your OG is 1.100 and anticipated FG is 1.020 you can continue to oxygenate during fermentation as long as you are still above 1.060.

Just look in pretty much every basic brewing technology text, be it Kunze or Narziß or Bamforth or whatever.

I'm really surpised that Whitelabs would hand out such bad advice, on the other hand they're in the business of culturing yeast and not making beer so they're not the first source I would turn to for advice on the latter topic.

Most of what I have seen is to do a second oxygenation at about 24 hours going by time rather than percentage of fermentation. Do you know how far the gravity might have dropped by then? I could see a quick start dropping quite a bit. And a slow start hardly dropping at all. So with the fast start you might be approaching that a little less than 50% to FG. And the slow start might really need the boost.

If you are less than 50% of the way to FG and you oxygenate, do you know that all the added oxygen is not consumed in the remaining fermentation?

 

[Day-Day]

I'm sure some have expensive equipment but not all... but you're right... you can hit your terminal gravity on those bigger beers without adding extra oxygen during active fermentation.

 

[RPh_Guy]

IF you use good brewing process and pitch a PROPER amount of yeast, then any oxygen added to beer is detrimental except at the time of pitching active yeast.

IF you use inadequate pitch rate, then additional oxidation MIGHT be beneficial as a crutch to help the yeast grow and to suppress off flavors or under-attenuation associated with underpitching.

White Labs suggests not making starters, right? It's no surprise they also suggest other poor practices to make up for under pitching. They aren't brewing scientists.

 

[Vale71]

White Labs suggests not making starters, right? It's no surprise they also suggest other poor practices too make up for under pitching. They aren't brewing scientists.

Not to mention the suggestion to pitch lager yeast warm and then cool at the first sign of fermentation, which is a recipe for a diacetyl bomb if I ever saw one...

 

[kh54s10]

IF you use good brewing process and pitch a PROPER amount of yeast, then any oxygen added to beer is detrimental except at the time of pitching active yeast.

IF you use inadequate pitch rate, then additional oxidation MIGHT be beneficial as a crutch to help the yeast grow and to suppress off flavors or under-attenuation associated with underpitching.

White Labs suggests not making starters, right? It's no surprise they also suggest other poor practices too make up for under pitching. They aren't brewing scientists.

I think you need to tell this to the brewers at Samuel Adams. I read something on their brewing of Utopia, which is over 20% ABV. Unless I am mistaken they do at least one if not several additional oxygen additions.

 

[kh54s10]

Not to mention the suggestion to pitch lager yeast warm and then cool at the first sign of fermentation, which is a recipe for a diacetyl bomb if I ever saw one...

Not necessarily. It would depend on the degree of difference and how long you stay at the warmer temperatures. I would say that if you stayed warm by just a couple degrees, just to start the fermentation, then dropped the temperature there would be not diacetyl... Now starting fermentation at 80 degrees and waiting 3 days to drop to 50 degrees......

 

[RPh_Guy]

I think you need to tell this to the brewers at Samuel Adams. I read something on their brewing of Utopia, which is over 20% ABV. Unless I am mistaken they do at least one if not several additional oxygen additions.

Sorry, I thought this went without saying:
Caveat: If you don't care about oxidation, then anything goes.

Utopias is barrel aged.

 

[kh54s10]

Sorry, I thought this went without saying:
Caveat: If you don't care about oxidation, then anything goes.

Utopias is barrel aged.

That doesn't mean that they don't add oxygen. I will have to look to see if I can find what I read. I doubt Samuel Adams would do it if it was a concern for oxidation.

 

[IslandLizard]

You can actually continue to oxygenate into fermentation on really big beers (>1.080) in order to increase yeast health and attenuation. This can be done as long as you are less than 50% to your goal FG. This information was given to me by a friend that went to a yeast lab boot camp recently.

Allegedly at one of those "boot camp" events White Labs' Chris White claimed making yeast starters is not necessary, just pitch one PurePitch pack and call it a day. Now this is from the same guy who co-wrote the Yeast book a few years ago. At least his name is on the cover and declared as being the co-author. There's a chapter on yeast starters and guidelines on wort/beer oxygenation before active fermentation has started.

So far, I have not oxygenated any of my beers. Seems to work okay. Using US-05 yeast either pitched fresh on new wort,

Dry yeast apparently does not benefit (as of late) from wort aeration/oxygenation, according to Fermentis' new usage instructions, neither does re-hydration before pitching. I'm not buying it without some conclusive proof. It could simply be a marketing ploy, making the process easier for aspiring and novice brewers, removing possible hurdles, and steering them away from other yeast products.

I oxygenate yeast starters, as well as (batch) wort right before pitching, occasionally right after.
(Super) high gravity beer (>1.090) is oxygenated again within 6-16 hours after pitching. That's before any signs of active fermentation, i.e., any krausen or foam are visible or any attenuation has occurred. I keep a close eye on those.

On a side note, I've had fermentations start within 3 hours after pitching an active vitality starter into well-oxygenated 1.055-1.065 wort. Active fermentation was often done within 2-3 days at 68-70F (WY1318). My best NEIPAs came from using these processes.

 

[RPh_Guy]

That doesn't mean that they don't add oxygen. I will have to look to see if I can find what I read. I doubt Samuel Adams would do it if it was a concern for oxidation.

I wasn't doubting what you said, simply pointing out that this beer will be oxidized from barrel aging. Therefore oxidation that happens easier in the process may not be relevant in that particular beer.

You could point to any number of oxidized beers from commercial breweries. That doesn't mean it's good practice to produce oxidized beer.

You can determine what's acceptable in your brew house.

Dry yeast apparently does not benefit (as of late) from wort aeration/oxygenation, according to Fermentis' new usage instructions, neither does re-hydration before pitching. I'm not buying it without some conclusive proof.

Anecdotally I get much shorter lag times with proper rehydration.

I'm also a big fan of vitality starters for the same reason.

 

[kh54s10]

I didn't find any reference to Utopias. But I did find plenty of posts where people are doing a second addition of oxygen on very high gravity beers. I don't think people would be doing this if it ruined their beers.

 

[RPh_Guy]

I didn't find any reference to Utopias. But I did find plenty of posts where people are doing a second addition of oxygen on very high gravity beers. I don't think people would be doing this if it ruined their beers.

What you're describing is called "anecdotal evidence". Anecdotal evidence is great for determining what's generally acceptable, especially when there's a lack of "scientific evidence".

On the other hand, "scientific evidence" is the result of controlled experiments designed to determine the results of changing specific variables. There's a large body of brewing research, especially coming from Germany where most brewers have degrees in brewing science.

"Good" and "ruined" are subjective terms.
Do you want to avoid the effects of oxidation in your beer? If you do and you want to optimize your methods to do that, fortunately we have scientific evidence that tells us exactly how.
We don't need to rely on anecdotal evidence like "well this one guy did it this way and didn't hate the result".