Yeast for O2 Cleanup in packaging

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redkegGV

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I've been working on implementing techniques to help reduce oxidation and off-flavors after bottling. I notice that my beers have very short shelf-life and it is a shame to dump bottles of beer because we simply can't drink it fast enough in its prime. The flavor I get is sweet, sherry-like most of the time, but often it's just a stale, old taste.... after only a few weeks in a bottle. I'm guessing it's an O2 problem, but I could be barking up the wrong tree.... going with my gut, here's my QUESTION:

If I keg, force carb, then bottle, is there a formula or a way to "microdose" a clean yeast to the bottles that will not dry out or change the character of the beer, won't add much additional carbonation, but will consume any O2 that inevitably enters the bottle when going from keg to bottle?

Background information to supplement my question:

1. I keg and force carbonate, but end up bottling quite a bit after carbonating, because I need to free up the keg for the next batch.

2. I bottle using the Blichmann Beer Gun. I also use clarity ferm regularly now as a standard part of my brewing process.

3. I'll admit that I could do better in whirlpooling and not picking up so much break into primary, but I do cold-crash and feel like I get quite clear results once its conditioned in the keg. I feel like most particles that would encourage off flavors are dropping out before hitting the bottles.

4. I understand that homebrew in itself is not going to carry much of a shelf life because I am not using chemical preservatives, or otherwise.

I am exploring the technique of krausening, in which a second actively fermenting batch of beer (starter) is pitched into the main batch just as fermentation slows. This is new to me and pardon the explanation if you already are an expert here. In researching this technique for cleaning up and speeding up fermentation completion, I came across a comment indicating that a big benefit of bottle conditioning is that the yeast are consuming any O2 remaining as part of the conditioning process. Duh. But it had never crossed my mind that this could also be used as a way to minimize oxidation from sloppy bottling to near 0.
 
If you add yeast without any fermentables, then it will just sit there, so you would need to add a little sugar as if you are bottle priming. I like using CBC-1 for bottle priming. Krausening is another technique that works, but you have the whole hassle of doing the math to figure out how much to add, and brewing a 2nd batch that will be ready at the perfect time.
Perhaps others who use a blichman can talk you through techniques on how to minimize your chances of oxidation. I'm sure it has been done.
Finally, addressing your #4, properly bottled beer can have a long shelf life- even multiple years depending on the style. Do a search on 'I found a 20-year bottle and it was great' type of posts.
 
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I doubt yeast will do much to clean up O2 in bottles once it's done with the priming sugar. When the food runs out the yeast goes to sleep. It's best to limit the introduction of O2 in the first place.

I'm a bottler, too, and I don't go through beer very fast (I'm the only beer drinker in my household). To extend the shelf life, I put them all in the fridge once they are fully carbed. Heat is a big factor, and keeping them chilled ensures that they taste good for months rather than weeks.
 
It sounds like your bottling process might be introducing the issue? Does your kegged beer stay “good” for far longer?

Everyone’s systems/process are different, but there’s no reason beer bottled from your keg tap shouldn’t last for months/years. Have you tried skipping the bottling gun and just using the tap? If you cap on foam, most O2 will be pushed out.
 
I doubt yeast will do much to clean up O2 in bottles once it's done with the priming sugar.

Indeed, but in general it should use all the O2 in a bottle before it's finished chomping the sugar.

As an aside, CBC-1 is a champagne yeast, there's nothing particularly special about it. I imagine F-2 is similar.
 
1. I keg and force carbonate, but end up bottling quite a bit after carbonating, because I need to free up the keg for the next batch.

Why? Your next beer can sit in the primary fermenter until the keg kicks. The it should be a quick process to clean the keg and refill. No more messing with bottles. I would suggest that you not leave the beer in the primary for an excessive amount of time. I'd define excessive as over 6 months.

3. I'll admit that I could do better in whirlpooling and not picking up so much break into primary, but I do cold-crash and feel like I get quite clear results once its conditioned in the keg. I feel like most particles that would encourage off flavors are dropping out before hitting the bottles.

4. I understand that homebrew in itself is not going to carry much of a shelf life because I am not using chemical preservatives, or otherwise.

You can skip the whirlpool and dump everything into the fermenter. Given sufficient time it all settles out and compacts down so it is easy to transfer to the keg without transferring the trub. In any case, the trub does not cause the off flavors you are worried about.

Homebrew can have a shelf life extending into years. It doesn't need chemical preservatives to do so. The enemy of shelf life is oxygen so one should try to minimize that, especially with hoppy beers.
 
Indeed, but in general it should use all the O2 in a bottle before it's finished chomping the sugar.

As an aside, CBC-1 is a champagne yeast, there's nothing particularly special about it. I imagine F-2 is similar.

How should it do that? I for example have never observed yeast jumping up out of the beer and absorbing O2 trapped in the headspace.
Besides O2 being only partly accessible to the yeast, aerobic metabolism is limited in its throughpout, hence most of the sugars will be fermented anaerobically leading to their exhaustion prior to all available oxygen being used up.
The greatest benefit of having unfiltered beer is that yeast in suspension will to some extent reduce undesirable compounds that stem from oxidative processes, reducing the extent of beer staling.
 
The
How should it do that? I for example have never observed yeast jumping up out of the beer and absorbing O2 trapped in the headspace.
Besides O2 being only partly accessible to the yeast, aerobic metabolism is limited in its throughpout, hence most of the sugars will be fermented anaerobically leading to their exhaustion prior to all available oxygen being used up.
The greatest benefit of having unfiltered beer is that yeast in suspension will to some extent reduce undesirable compounds that stem from oxidative processes, reducing the extent of beer staling.

the oxygen and CO2 and other gasses dissolve in the beer where the yeast can access them.
 
Don't rule out your 7ppb of o2 ingress per day though the cap!

Active yeast can consume about 8ppm of o2 per hour.

Temperature + o2 = super accelerated staling. Chemical reactions happen 10x faster per 1c raise in temp..
 
Don't rule out your 7ppb of o2 ingress per day though the cap!

Active yeast can consume about 8ppm of o2 per hour.

Temperature + o2 = super accelerated staling. Chemical reactions happen 10x faster per 1c raise in temp..

I won’t comment on the cap O2 statements, but your chemical reaction statement is beyond false.

Arrhenius equation suggests rates double every 10C increase. This is an oversimplification as different reactions will have different kinetics.

Just an FYI
 
I won’t comment on the cap O2 statements, but your chemical reaction statement is beyond false.

Arrhenius equation suggests rates double every 10C increase. This is an oversimplification as different reactions will have different kinetics.

Just an FYI

You are completely correct, thats my fault for trying to multitask. I flopped some stuff around.

However the bottle cap and the Yeast thing are correct!
 
The


the oxygen and CO2 and other gasses dissolve in the beer where the yeast can access them.

Given time yes, but this doesn't happen overnight (if it did, bottled beer would stale even faster) and by the time all the oxygen has moved to the beer:

A- The yeast has long gone to sleep as it has nothing to eat any more.
B- The beer has noticeably staled.
 
Beer contains natural antioxidants as well. Sulfur, and ascorbic acid oxidase to name a few. The more rigid you are on the cold side the more of these you preserve which will help the shelf life of the beer. However some oxidative reactions can occur in the absence of oxygen as well. Namely the breakdown of fats and lipids ( that come from the malt, and trub carryover)
 
Given time yes, but this doesn't happen overnight (if it did, bottled beer would stale even faster) and by the time all the oxygen has moved to the beer:

A- The yeast has long gone to sleep as it has nothing to eat any more.
B- The beer has noticeably staled.

It literally is overnight!
I worked in the lab at Bud and measuring TPO - Total Pack Oxygen - is a key quality check for bottles going out. Especially due to the light taste which would show oxidation earlier than other beers.
To equalise the gasses in the beer and headspace you’d vigorously shake the bottle for a couple of minutes. However if you didn’t do this you could just leave the bottle to stand for a couple of hours.
After this time the ratio of gasses in the headspace would match those in the beer.
 
Matching ratios is something else as "all the oxygen has migrated to the beer". Depending on bottling system (and I'm sure Bud had much better systems than your average homebrewer) there can still be a lot of O2 in the headspace which will slowly migrate to the beer as the already dissolved oxygen gets consumed, either chemically or biologically.
To think that you can solve this thanks to yeast is just wishful thinking.
 
Matching ratios is something else as "all the oxygen has migrated to the beer". Depending on bottling system (and I'm sure Bud had much better systems than your average homebrewer) there can still be a lot of O2 in the headspace which will slowly migrate to the beer as the already dissolved oxygen gets consumed, either chemically or biologically.
To think that you can solve this thanks to yeast is just wishful thinking.

If you prime the beer and the yeast is active it will use the oxygen in the beer.
This will cause an imbalance in the ratios of gasses in the headspace and the beer and so dissolve more O2 in the beer. This will be used by the yeast and so on until the yeast goes dormant or uses all the oxygen.
 
If you prime the beer and the yeast is active it will use the oxygen in the beer.
This will cause an imbalance in the ratios of gasses in the headspace and the beer and so dissolve more O2 in the beer. This will be used by the yeast and so on until the yeast goes dormant or uses all the oxygen.

There are just not enough fermentables in the bottle for the latter to happen, hence the former will always be the case. Because of the Crabtree effect yeast will metabolize most of the sugar anaerobically and run out of it way too soon.
Besided that, O2 that gets dissolved in the beer will not purposefully direct itself towards the closest yeast cell, it still has to travel through the beer and some of it will react with beer constituents causing some staling, irrespective of residual yeast activity. That is the reason why you must not oxygenate wort once the yeast has started fermenting, even with the huge amount of active yeast you have in fermenting wort you will still cause some staling even before the beer has made it to the final package.
 
This is a part of an email correspondence I had with Andy Mitchell over at New Belgium brewing on the topic of TPO:

"From what we have seen here at New Belgium, if there is any yeast, even if there is no sugar, they will quickly reduce TPO significantly. Because most of our beers are pasteurized, we will often add yeast back to finished bottles and cans, even that are already carbonated, to reduce TPO. I think having any food (sugar) would make this process work better"
 
There are just not enough fermentables in the bottle for the latter to happen, hence the former will always be the case. Because of the Crabtree effect yeast will metabolize most of the sugar anaerobically and run out of it way too soon.
Besided that, O2 that gets dissolved in the beer will not purposefully direct itself towards the closest yeast cell, it still has to travel through the beer and some of it will react with beer constituents causing some staling, irrespective of residual yeast activity. That is the reason why you must not oxygenate wort once the yeast has started fermenting, even with the huge amount of active yeast you have in fermenting wort you will still cause some staling even before the beer has made it to the final package.

I oxygenate my RIS for the last time 3 days after pitching, before it gets to high krausen. It's obviously already fermenting at that point. Nothing is off with it and it even won me a medal in the nationals the one time I entered it.
 
Very interesting discussion!

Does anyone know of actual data versus just qualitative analysis? Specifically looking at some kind of quantification for beer bottles stored with and without yeast.

I found a post on a LoDo website, but I didn’t see DO measurements or even triangle test data.

Thanks!
 
Very interesting discussion!

Does anyone know of actual data versus just qualitative analysis? Specifically looking at some kind of quantification for beer bottles stored with and without yeast.

I found a post on a LoDo website, but I didn’t see DO measurements or even triangle test data.

Thanks!
I feel certain that someone will have measured the O2 change in bottle conditioned beers.
Had a quick google scholar search and found a PhD thesis that looked at DO2 levels.
https://ir.library.oregonstate.edu/downloads/h128nh97c

Seems to show a drop in levels over 5 months then an increase after that. Worth having a look at.
 
I feel certain that someone will have measured the O2 change in bottle conditioned beers.
Had a quick google scholar search and found a PhD thesis that looked at DO2 levels.
https://ir.library.oregonstate.edu/downloads/h128nh97c

Seems to show a drop in levels over 5 months then an increase after that. Worth having a look at.

It looks like the DO2 levels were already quite high (>500 ppb), so I wonder if that confounded the data?
 
It looks like the DO2 levels were already quite high (>500 ppb), so I wonder if that confounded the data?
That sparked a memory from somewhere. I worked at a cask ale brewery many years ago and the spec for beer to be racked was 0.3ppm DO2. So maybe that’s not so high for a beer that will be conditioned.
 
Yea thats wicked high. I don't bottle anymore but I do can and my cans average between 22-24ppb with an orbisphere. However my kegs are filled from the fermenter with extract remaining, thereby eating all the o2 from the transfer and naturally carbonating. Even with the minimal uptake of o2 on canning, I can always pick out the canned beer in tests.


I did a write up of my method to bottling.
http://www.********************/uncategorized/low-oxygen-bottle-filling/
 
Yea thats wicked high. I don't bottle anymore but I do can and my cans average between 22-24ppb with an orbisphere. However my kegs are filled from the fermenter with extract remaining, thereby eating all the o2 from the transfer and naturally carbonating. Even with the minimal uptake of o2 on canning, I can always pick out the canned beer in tests.


I did a write up of my method to bottling.
http://www.********************/uncategorized/low-oxygen-bottle-filling/

Nice post, but where’s the rest of your follow up data! And is your DO2 meter indicating single digit ppb values?
 
The earlier bottle cap comment about 2 ppb 02 ingress per day is not accurate. That study was done 28 years ago and even then they said that the inclusion of pasticiziers in the PVC liner resulted in ingress of 0.00 ppb over time. Since then most bottle caps are a combination of blended barrier and 02 absorbing. The issue now is not 02 ingress, but that all those nice hop aromatics/oils are being absorbed into the crown liner. No one is talking about it, but can liners are another issue. That said, crown liners are not indestructible and will ingress 02 over long periods of time, ect.

Furthermore, proper TPO testing must be done immediately after filling. Sending samples out to a lab is moot, since the oxidation reactions happen very quickly and the resulting readings are not accurate in terms of original oxygen concentrations.

Per the yeast v without, I'll have to dig up the papers, but there was a significant difference in sensory between the two. Considering the trouble breweries like Sierra, Deschutes, and NB go to ensure there is live yeast in the bottle... is it even worth arguing over?
 
Nice post, but where’s the rest of your follow up data! And is your DO2 meter indicating single digit ppb values?

Yea kinda forgot about it.. long story short the beer started really showing signs of deterioration. Yes, thats correct.

Did a full write up on cold side o2 and numbers on the blog, where we have the numbers.
 
I suspect the best place to look would be British sources, as CAMRA pressure means that bottle conditioning is a bit more of a thing commercially here, even though the retailers hate it. And you hve the likes of Moor Beer who got CAMRA to change their rules to accommodate can conditioning.

Anecdotally - there was quite a bit of talk about using yeast to control oxygen in small-pack 2-3 years ago as people began to think more about DO but that chatter seems to have fallen away presumably as packaging technology has improved. I'll ask around - thinking about it this would have been an ideal question for John Keeling of Fuller's when I was chatting to him the other day.

Just as some benchmarks :

Sample numbers from Hach :
Industry standard oxygen levels throughout the brewery
In wort 8 – 17+ ppm
Fermentation< 10 ppb
Filtration 5 – 50 ppb
Bright beer after filtration 10 – 50 ppb
Beer at the filler 10– 30 ppb
Package dissolved O2 (bottle) 20 –50 ppb
Package dissolved O2 (can) 30 – 60 ppb
Total package dissolved O2 40 – 150 pp

The latest canning machines are claiming 5-20ppb pickup.

In the real world, this presentation from Pelican Brewing talks about this stuff from the perspective of an ordinary brewery trying to bring an elderly bottling line up to modern standards (with the top tip - make friends with your local Harley Davidson dealer!). Initially they were >2000ppb DO but have now got it down to 45-60ppb raw DO in bottle, equivalent to TPO 107-142ppb with a long-term target of <100ppb TPO.

Pelican reckon >150ppb or on a hoppy beer >200ppb on their cream ale is noticeable after 3 weeks of 65-70F storage, 4 months refrigerated. So I guess that's another aspect - how much effort do you want to put into minimising O2 versus just sticking stuff in the fridge?

Cloudwater, who are pretty much the benchmark for hoppy beer in the UK, recently tweeted this :
"11ppb O2 in FV. 30-40ppb O2 during the [centrifuge] run (carbonating inline before the centrifuge), and 11ppb O2 in Brite Beer Tank...<50ppb is our target in can."

ISTR them talking about hitting 20ppb in can at some point - and since they were something of pioneers, I suspect the latest kit can do better. These guys boast about a 15ppb canning run.

I'm sure I've seen Moor talking actual numbers for their can conditioning but can't find it off a quick Google.
 
As seen by my blog post I am at around low 20's (ppb) in the can for my setup. I am seeing 9months+ for stability. I am happy with that.
 
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