Get into O2 guys, if you're serious about nicer beer

[manticle]

I'm familiar with complex simplification techniques.

 

[SBOB]

Has anyone ever heard of getting a small oxygen cylinder, maybe a reg and some line/tube and actually blowing actual oxygen actually into the wort?
Might sound silly but could be an option.......

We have, but then someone posted a thread about whether a reg was O2 compatible and everyone gave up

 

[Bribie G]

Could cause excessive frothing.

 

[Bribie G]

Back on track, my 1.050 APA was pitched on Thursday night after a blast of O2 and by Sunday night was clearing from the top, so after a D rest, today (Tuesday)I'm dropping it 4 degrees per day then a week at -1.



Oops did I say dropping?

 

[Adr_0]

Could cause excessive frothing.

Is that in the fermenter or in the mouth of the beer drinker?

 

[sp0rk]

Is that in the fermenter or in the mouth of the beer drinker?

Neither, in the pants...

 

[Adr_0]

Neither, in the pants...

Oohh. A quick jet of O2 does sound nice...

 

[Phoney]

so after a D rest, today (Tuesday)I'm dropping it 4 degrees per day then a week at -1.

What's the idea behind a staggered cold crash, rather than just straight from D rest to -1 as quickly as your freezer can get it there?

 

[warra48]

What's the idea behind a staggered cold crash, rather than just straight from D rest to -1 as quickly as your freezer can get it there?

Attemporates your yeast gradually and keeps them from going into hibernation from a rapid drop in temperature, thus continuing to assist in cleaning up your beer.
At least, I think that's the theory.
Better brains than mine feel free to jump in here.

 

[Bribie G]

I intend to re use the yeast cake, so treating the little fellas with respect rather than a sledgehammer.

 

[technobabble66]

FWIW, i pitched a Rogers' Ale clone (OG=1.040) onto a M44 yeast cake yesterday. After a little vigorous stirring of the wort, i used ~1.5mL of 35% H2O2 solution (so v similar dosing rate to the others here, i believe), added after pitching, of course.
Today, ~20hrs later, there is a large healthy looking krausen and the SG=1.034, temp has been held at 19°C the whole time.
Given this is pitched onto a large yeast cake, this is hardly a definitive display of oxygenation/success.
However, it might be worth noting the yeast doesn't appear to have died/struggled and is looking healthy & vigorous.
Again, not surprising on the 2nd use of a yeast cake, but i just thought i'd report what's happened.

 

[manticle]

I think actual fermentation time, attenuation and reduced ester level are the main indicators rather than lag time or krausen apperance.

Every time I look at this thread, I want to get a set up. So many costs over the end of last year that have made that harder but hopefully not too much further away.

 

[peteru]

The entry cost for H2O2 method is under $10 for at least 10 batches, if you are happy with pharmaceutical grade H2O2.

The Gold Cross brand uses phosphoric acid as the main stabiliser. It also contains phenacetin (precursor to paracetamol), which used to be sold as a pain-reliever up until to 80s. Phenacetin is no longer used as a pain reliever and has been replaced by paracetamol, due to concerns that in large doses it can cause kidney damage. I am not too concerned about the phenacetin content while I experiment with the technique. The exposure will be fairly minimal given the dilution rate and rate of consumption. If I decide to continue with the H2O2 technique, when I finish the bottle of H2O2 that I have, I'll try to source something without stabilisers. This will probably increase the cost and require more careful handling, thus defeating some of the advantages of the H2O2 method. It's still likely to have lower entry cost than compressed O2 and require less equipment.

I have now done a 3-way test using this Oxygenation method. Same wort split three ways:

1. No H2O2, just stir/shake aeration, fermented without temp control at 20-24C
2. H2O2 6% v/v at a rate of 12mL/20L, fermented without temp control at 20-24C
3. H2O2 6% v/v at a rate of 12mL/20L, fermented at 18C

All three batches started at 1.056 and finished 1.004, using the same US-05 starter. The two batches without temp control were smaller in volume than the main batch fermented under temperature control.

It is no surprise to learn that the temperature controlled batch ended up tasting the cleanest and fermented a little slower.

There was a significant difference between the flavour and aroma of samples 1 and 2. Sample 2 had significantly more esters with hints of green apple and finished fermentation one day faster than sample 1. Sample 1 ended up having less hop aroma and bitterness and the krausen was never as big as sample 2. Admittedly, this is not a very useful test because both samples produced substandard beer due to inappropriate fermentation temperature and lack of temperature control. However, it is interesting to see that the addition of H2O2 does make a difference to the fermentation process and affects the flavour. I was surprised to see more esters and acetaldehyde in the oxygenated wort, but perhaps that will clean up over time.

More experimentation is required. I have batch of MO/Columbus SMaSH ready for pitching tonight. I'll do the main batch with H2O2 and get a small sample without H2O2 next to it in the fermentation chamber. There's not much spare room, but I'll see what I can do.

So far I have not produced a beer with the addition of H2O2 and proper temperature control, where I would have detected fermentation faults.

 

[Phoney]

I once read a many, many page long thread on HBT (I think) on using H2O2 for oxygenation of wort, there were comprehensive experiments done and smartpants with chemistry degree's chiming in and the general consensus was that it was a silly idea. Stick to real oxygen or shaking.

 

[Adr_0]

I once read a many, many page long thread on HBT (I think) on using H2O2 for oxygenation of wort, there were comprehensive experiments done and smartpants with chemistry degree's chiming in and the general consensus was that it was a silly idea. Stick to real oxygen or shaking.

Sounds pretty definitive. I'm pretty sure I read on that forum someone with 'Doc' or 'Dr' or 'The Doc' trying this, but massively over-estimating the H2O2 required. Sure enough, he reported the results and everyone got on board. Sometimes doctors, scientists and engineers get a little too caught up in the fine focus stuff and don't think in practical terms. I still go back to my dosage argument - it's a little similar to zinc: too much zinc is toxic to yeast isn't it?

I would like to get my hands on this study as it sounds interesting:
http://www.jbc.org/content/273/35/22480.full

The gist of that one is that quite a lot of eukaryotes have defense mechanisms for H2O2 as it's something they encounter quite a lot in nature, believe it or not. They need to still be able to function under oxidative stress. That article appears to suggest Saccharomyces cerivisae is one of those beasts.

The catalase enzyme in yeast is the sucker wot grabs the 2H2O2 and breaks it down into 2H2O + O2. The rest of the cell then absorbs the O2. Being a catalyst, it's not strictly a reactant and should not change - except perhaps for extremely high doses of H2O2... but I am curious about this.

I'll try and do a split batch shortly, but also trying to do one thing at a time...

 

[technobabble66]

I once read a many, many page long thread on HBT (I think) on using H2O2 for oxygenation of wort, there were comprehensive experiments done and smartpants with chemistry degree's chiming in and the general consensus was that it was a silly idea. Stick to real oxygen or shaking.

Hey Phoney, is this the thread on HBT you're referring to?
I've just gone through it. I'd suggest it's not actually that productive a conversation really.
It was basically concluded by a poster who said he was a chemist and it was a stupid idea. He seemed to have a firm idea on some of the unpredictable and potentially damaging chemistry involved in using H2O2 and left it there.
There was also some input from a guy saying he had a biology background and basically H2O2 was damaging to both the cell walls but also the DNA.
I'd be reluctant to completely disregard their opinions and say they're wrong, but they definitely seem to have looked at a very narrow aspect of what is going on with the H2O2 technique and decided a firm conclusion from that. I have a Biochemistry/Molecular Biology background and i'd be fairly confident in assuming things are a lot more complex than simply deciding H2O2 can kill/damage living cells and could react with the components of the wort. Note that i'm aware they are still valid points, so i'm not disregarding these issues. To be fair to the 2nd guy i mentioned, he does point out that most organisms form proteins to degrade Reactive Oxidative Species so he does seem to appreciate some of the complexity at play as well.

There's also the minor technicality that a paper was published a year after that thread (in 2012) that illustrated the rapid degradation of H2O2 by Baker's Yeast, and convinced me that this H2O2 thing might actually be viable without damaging the yeast or the wort.

EDIT: This is the paper i'm referring to.

I'd also point to the enormous **** storm that occurred around the belief of cubing/no-chill being impractical/dangerous until enough people tried it and survived, and went on to produce award winning beers. Botulism, anyone?
I'm not saying i'm totally convinced on the H2O2 technique. However, the science behind it is quite plausible - both in effect and "safety" (i.e.: no damage to yeast/wort) aspects - and initial results seem at least ok. I don't think any of us as yet have reported a good comparison of results between an H2O2 batch and one without (& preferably one done with O2). But there's at least a few initial reports of batches that haven't gone bad. Much more work to be done! (probably by Peteru, as my process won't support good comparisons - i.e.: no parallel ferments, etc).


And @Manticle, i'd definitely agree: lag time & krausen are no real indicator of best fermentation at all (it's just all i had to report ).
From some more recent reading i've done, it can actually be the case that a shorter lag phase and a rapid krausen formation can indicate a stressed and less adapted yeast. So i'd further agree the only way the gauge the success/improvement or failure of this technique with be in attenuation rate and extent, plus the "cleanliness" of the finished beer.
Hence, more testing required.

EDIT: @Adr, just went through that paper. V interesting, and thanks v much for linking it. What i found most relevant was the speed of the yeast response - all reacting within minutes, and production of the enzymes done and finished within 30-60mins. And also the flowchart of what's enhanced/repressed in the biochemistry pathways:

Seems like the TCA cycle, GMP, polyamine & ethanol are repressed; whereas Glycerol metabolism & NADPH is increased.
TBH, i'm not sure what the consequences would be of all that, with regards to what we're interested in. But the fact ethanol is repressed and that also what occurs during the growth/adaption phase (which is what we want to enhance) is maybe slightly reassuring it's not too bad. :mellow:
Probably the main reassurance is the fact the response is so rapid and, most importantly, the production of the enzymes relating to the stress response drop back within an hour or so. To me this suggests the yeast is likely to be only temporarily affected or "stressed" by the presence of H2O2, after which it returns to a "normal" state and proceeds to adapt & multiply B)

 

[GalBrew]

I'm hearing a lot of blather on either side at the moment. Some proper experiments to work out if it is beneficial or not is in order. It may be the case that it is neither of any benefit nor is it detrimental. We are all dealing in anecdotes at the minute.

Does anyone have access to qPCR and has primers for an array of yeast stress genes? Would be interesting to see how the 'low' concentration of peroxide affects the yeasties.

 

[Adr_0]

I'm hearing a lot of blather on either side at the moment. Some proper experiments to work out if it is beneficial or not is in order. It may be the case that it is neither of any benefit nor is it detrimental. We are all dealing in anecdotes at the minute.
Does anyone have access to qPCR and has primers for an array of yeast stress genes? Would be interesting to see how the 'low' concentration of peroxide affects the yeasties.

You're actually hearing a lot of theory put forward by scientists and engineers, and a couple of experiments, which have perhaps not been that well controlled.

Why don't you do a controlled experiment and enlighten us?

I'm going to do a split batch of H2O2 and no O2/H2O2 with dry yeast at some point but probably not in the next week.

 

[GalBrew]

You're actually hearing a lot of theory put forward by scientists and engineers, and a couple of experiments, which have perhaps not been that well controlled.

Why don't you do a controlled experiment and enlighten us?

I'm going to do a split batch of H2O2 and no O2/H2O2 with dry yeast at some point but probably not in the next week.

I think we have sufficiently fleshed the theory out around the potential actions of hydrogen peroxide in wort. What we need now is some data. Now I will freely admit that I have neither the equipment nor the inclination to do this justice, but to convince this scientist of the merits of hydrogen peroxide additions to fermenting wort I would like to know the following:

1. How does the addition of hydrogen peroxide affect DO levels in the wort?

2. How does the addition of hydrogen peroxide affect the number and/or vitality of yeast in the fermenting wort?

3. How does the addition of hydrogen peroxide affect the degree and rate of attenuation?

I am of course open to any other ideas. I look forward to seeing your results. The only issue I would put forward is using dry yeast. Most dry yeast manufacturers suggest that using oxygen is not required due to the 'health' (energy reserves, etc) of the yeast when they are dried. A liquid yeast would be a better choice as they are not in prime condition when we get them and benefit from a starter.

Anyhow, good luck. I'll pipe down now.

 

[mstrelan]

Yeah I wouldn't trust any experiments that didn't have temp control. 20-24? I bet it got hotter than that.