Dissolved Oxygen Experiment- Interesting Finds with Beer Transfer Method

[Bilsch]

How about just being polite and offering constructive criticism and helpful guidance? It might serve you better and result in your audience being more receptive, just a thought.

I agree that would be the best approach and I tried that first with comments to the original review however that was ignored. Also we’re not talking about a post here that was a bit misguided but instead a review of a DO meter out in the wild that by all appearances purported to be from a person qualified to do the work. Yes I definitely could have been nicer but things like that raise my hackles.

To the OP: I hope you take the time to learn more about this fascinating subject and possibly think about going back and correcting your review.

 

[Bilsch]

So breweries look at oxygen pickup from step to step instead of focusing entirely on TPO at the end?

Could you work around this limitation doing the experiments with deoxygenated water? Perhaps water treated with yeast and sugar and then boiled before being put into a purged conical?

Breweries don't bother looking at DO numbers in the mash but some do check the DO of the strike water and in the piping/tanks before transfer etc. then finally TPO. But remember TPO can’t tell you what oxidation happened in the brewing process, only what was picked up during bottling/canning.

Sure you can check out the tightness of your system by running DO water through it and looking for oxygen ingress. Lots of LoDO guys who own the correct in-process meters do this very thing. You’d be surprised the places that oxygen can sneak in.

 

[eric19312]

Breweries don't bother looking at DO numbers in the mash but some do check the DO of the strike water and in the piping/tanks before transfer etc. then finally TPO. But remember TPO can’t tell you what oxidation happened in the brewing process, only what was picked up during bottling/canning.

Sure you can check out the tightness of your system by running DO water through it and looking for oxygen ingress. Lots of LoDO guys who own the correct in-process meters do this very thing. You’d be surprised the places that oxygen can sneak in.

Thanks - yes good to know that's a way to get useful results (once you have access to a good enough meter).

 

[micraftbeer]

I agree that would be the best approach and I tried that first with comments to the original review however that was ignored.

I don't see anything on the website. I submit my reviews to the owner of HomeBrewFinds, who publishes them. I'll see if he had some comments there and if he can forward them to me. One thing I will update is the fact that the experiment of finished beer is trying to measure something in the 20 PPB region, whereas the MW600 has an accuracy of +/- 300 PPB. So that's essentially pointless.

As for the inability of the MW600 polarographic DO meter of measuring DO in wort, I'm going to want to reach out to Milwaukee to get their read on this.

Thanks for the feedback.

And by the way, I'm not offended by this exchange, it's been a ball!

 

[TheMadKing]

Breweries don't bother looking at DO numbers in the mash but some do check the DO of the strike water and in the piping/tanks before transfer etc. then finally TPO. But remember TPO can’t tell you what oxidation happened in the brewing process, only what was picked up during bottling/canning.

Sure you can check out the tightness of your system by running DO water through it and looking for oxygen ingress. Lots of LoDO guys who own the correct in-process meters do this very thing. You’d be surprised the places that oxygen can sneak in.

So honest question on this, because something isn't adding up to me:

If the creation of oxidation compounds occurs very rapidly (on the order of seconds to minutes) during the mashing process, so rapidly that you have to continuously monitor the DO level to catch it, doesn't oxygenation for yeast at the end of the boil create those compounds at the same speed? Meaning the no matter how careful you are throughout the process, it's all undone in the 2-4 hours needed for yeast to consume all the oxygen?

 

[madscientist451]

no matter how careful you are throughout the process, it's all undone in the 2-4 hours needed for yeast to consume all the oxygen?

Be careful, if you continue to question LODO dogma, you'll be burned at the stake.
Just kidding
(sort of)

 

[doug293cz]

Be careful, if you continue to question LODO dogma, you'll be burned at the stake.
Just kidding
(sort of)

Please don't go there in this thread. We have a separate sub-forum for discussing LoDO techniques.

doug293cz
HBT Moderator

 

[VikeMan]

I didn’t really want to pound on this guy in the open forum but instead posted a reply to the review where is was originally published in hopes the author would make attempts at correction but that was ignored.

I just had a look at the review. There are (currently) no comments there. Failed Post? Deleted? ¯\_(ツ)_/¯

 

[Bilsch]

So honest question on this, because something isn't adding up to me:

If the creation of oxidation compounds occurs very rapidly (on the order of seconds to minutes) during the mashing process, so rapidly that you have to continuously monitor the DO level to catch it, doesn't oxygenation for yeast at the end of the boil create those compounds at the same speed? Meaning the no matter how careful you are throughout the process, it's all undone in the 2-4 hours needed for yeast to consume all the oxygen?

It’s a good question and often the first one people ask when they start to contemplate why anyone would want to reduce oxygen exposure on the hot side when they are just going to aerate the wort before pitching.

The important thing to understand is that heat increases the kinetic energy of molecules therefore chemical reactions happen faster at higher temperatures. This means that the same staling reactions that take minutes in the mash will be slowed down to hours or days after chilling in the fermenter. Healthy yeast are quite capable of mopping up all available DO in less than an hour providing the protection to save your wonderful fresh malt/hop flavors and aromas from being oxidized.

 

[Bilsch]

I just had a look at the review. There are (currently) no comments there. Failed Post? Deleted? ¯\_(ツ)_/¯

Huh.. I wonder why replies questioning the accuracy of a glowing review could fall into a black hole never to been seen again. Also I wasn’t the only one who attempted to comment so i doubt it was an accident they vanished.

 

[Qhrumphf]

It’s a good question and often the first one people ask when they start to contemplate why anyone would want to reduce oxygen exposure on the hot side when they are just going to aerate the wort before pitching.

The important thing to understand is that heat increases the kinetic energy of molecules therefore chemical reactions happen faster at higher temperatures. This means that the same staling reactions that take minutes in the mash will be slowed down to hours or days after chilling in the fermenter. Healthy yeast are quite capable of mopping up all available DO in less than an hour providing the protection to save your wonderful fresh malt/hop flavors and aromas.

This.

Even at fermentation temps oxygen uptake, and the initial series of oxidation reactions, is quick (you measure DO in a brite tank during/immediately after a transfer vs the next day you'll see a noticeable difference), but yeast are quicker. If the assertion of the rate of oxidation to temperature as logarithmic is assumed to be true (which the chemistry suggests, and sensory for cold storage vs room temp vs hot storage of finished beer also validates), mash sparge and boil temp oxidation rates are orders of magnitude higher than fermentation temps.

 

[TheMadKing]

It’s a good question and often the first one people ask when they start to contemplate why anyone would want to reduce oxygen exposure on the hot side when they are just going to aerate the wort before pitching.

The important thing to understand is that heat increases the kinetic energy of molecules therefore chemical reactions happen faster at higher temperatures. This means that the same staling reactions that take minutes in the mash will be slowed down to hours or days after chilling in the fermenter. Healthy yeast are quite capable of mopping up all available DO in less than an hour providing the protection to save your wonderful fresh malt/hop flavors and aromas from being oxidized.

Thanks! Do you know if anyone has done the kenetics analysis of these reactions and produced a graph showing the reaction rate values of some of the major the oxidation compounds over a typical brewing temperature range? I'd like to see that data

My experience is limited to kenetics in actinide chemistry over a pH range and while there is certainly some variation in the values I don't recall having seen such a wide range from seconds to an hour+, so that's surprising.

Edit I found this paper which is interesting but it's post packaging only, but the temperature range is right

https://www.agraria.com.br/extranet...kinetics_of_beer_ageing_and_1601494802462.pdf
Edit edit

A more fundamental question is: what exactly are the reactions in pre-fermentation wort? I can find lots of papers in cold side and packaged oxygen and the reaction series in that solution, but very little on the hot side. So what oxygen sensitive flavor active compounds are being produced (or rendered non-flavor active) during the wort production process?

 

[Climb]

What was the DO reading of the worts?

 

[micraftbeer]

The important thing to understand is that heat increases the kinetic energy of molecules therefore chemical reactions happen faster at higher temperatures. This means that the same staling reactions that take minutes in the mash will be slowed down to hours or days after chilling in the fermenter.

OK, so here's how I'd sum this up. Let me know if I'm summarizing correctly, and then I've got two questions.

Dissolved Oxygen doesn't remain as DO in the presence of wort & beer, it goes through chemical reactions to create various oxides. In the end, as brewers, we're worried about minimizing the oxides. And DO is an indicator of the potential of our mixture to create oxides. However, since these oxidizing reactions are happening in real time, we're measuring DO as it's being consumed. At hot temperatures this happens quickly versus at room temperatures.

And has been pointed out, when looking at finished beer, the staling level we're concerned about is in the range of 20 PPB, whereas the MW600 has accuracy in the +/- 300 PPB range, meaning it's essentially pointless to try to measure this, and even comparative measurements will be complicated to avoid introducing air in the sampling/measuring process itself.

Sound right?


Here's my questions:

1. Do the same DO-consuming reactions happen in water? Is measuring strike water DO something that works?

2. I think the only one of my tests where I measured DO on hot wort was when I took some samples from the boil kettle to measure pre and post boil. (The other ones were with cool wort or with water.) And in that case, I had to cool it down (put it in a shallow dish to cool in the air before putting in a glass to submerge the measurement probe in once it had cooled to room temperature. Any measure on how fast the DO gets consumed at mash or boil temperatures? In other words, if you took a sample of hot wort right after you performed some process you were interested in, and then cooled quickly, would you be able to cool it fast enough to get a read on the DO that was present in the hot state?

 

[micraftbeer]

Huh.. I wonder why replies questioning the accuracy of a glowing review could fall into a black hole never to been seen again. Also I wasn’t to only one who attempted to comment so i doubt it was an accident they vanished.

As I mentioned before in this string, I don't own/run the website, I write equipment reviews and he publishes them. I'll reach out to him to see what's up with the Comments. If the comment was similar to what was earlier in this string "This is all garbage, go educate yourself", he might have found that non-specific and not really productive, and punted it. He will usually tell me if people post comments/questions so I can look at them and respond. I'll let you know what I find.

 

[Spivey24]

Yes, the more I learn about DO the more frustrating it is for homebrewers. That is why active yeast is your friend. They will clean up the O2 beyond our measurement levels on the cold side. On the hot side, faith and good information is about is good as a low cost meter.

How does one introduce active yeast into a closed transfer without doing more harm than good? And at what temperature would you do this?

 

[Bassman2003]

The active yeast comes from transferring to your keg with about 3 to 5 gravity points left in fermenttion and letting the beer finish in the keg. All the while, capturing the CO2 to naturally carbonate the beer.

 

[Bilsch]

Since this is now veering hard into the most interesting and technical aspects of low oxygen brewing I’m going to step away from those topics on this thread so as to not break forum rules. For anyone interested in going further down that rabbit hole.. you all know by now where the entrance is at.

 

[micraftbeer]

Huh.. I wonder why replies questioning the accuracy of a glowing review could fall into a black hole never to been seen again. Also I wasn’t to only one who attempted to comment so i doubt it was an accident they vanished.

I want to reply to this, as my integrity was being questioned. I just discussed with the website owner. If any of you use WordPress for a website, and allow comments on articles, you'll understand this. But these are huge targets for spammers out on the web. On my simple little website I get lots of people trying to sell me Cialis, asking where to go to get a good haircut in my area, and then random stuff in Chinese and Russian characters. HomeBrewFinds pays a service to filter through all of this, and he said this service has blocked literally millions of spam comments.

Those that don't get blocked by spam service go to him for review if they are a first-time user (subsequent posts by same person don't). He deletes comments that he finds when they are inappropriate, unhelpful, off topic or obviously self-serving (usually another vendor). @Bilsch 's comment was awaiting his approval, which he did. It was a couple weeks ago (pre-Thanksgiving), and I can't speak for the frequency of how often he reviews comments pending review.

But nothing malicious or conspiracy-related here.

And by the way, I'm working to gather further info to adjust the review/experiments to put them in the context of the good discussion we've had here.

 

[Bilsch]

But nothing malicious or conspiracy-related here.

And by the way, I'm working to gather further info to adjust the review/experiments to put them in the context of the good discussion we've had here.

Very happy to hear that you are considering some corrections. That really is the most important thing that can come of all this.

Remember though that measuring oxygen uptake in the brewing process is 4th year brewing university level and will take some time to fully grasp. May I suggest you limit your review of the MW600 to simply measuring DO in water and when oxygenating pre-pitch since that’s all this meter is really capable of doing. Limiting the scope should make the job easier. Consider concentrating more on how to setup, calibrate and then confirm the meters function with zero solution.

Be glad to help if you run into issues. Also maybe think about posting the drafts of any corrections here so everyone can weigh in on it.

Hope that helps.

 

[CascadesBrewer]

If any of you use WordPerfect for a website...

Maybe that is the issue. You should talk to him about upgrading to something more modern...like WordPress! Yeah, it is a good day when my spam to legit ratio is only 50:1. If anybody needs leads on increasing their customer retention, or is looking for a vape shop, or CBD, or lingerie, just let me know!

 

[micraftbeer]

WordPerfect... Probably shows my age. Or anyone that knows what that program is!

 

[VikeMan]

WordPerfect... Probably shows my age. Or anyone that knows what that program is!

WordPerfect for DOS, run off 5-1/4" floppies.

But actually, WordPerfect for Windows still exists and is still supported. I think the latest version was just last year.

 

[sibelman]

@Bilsch wrote: "... measuring oxygen uptake in the brewing process is 4th year brewing university level..." <sigh> I'm doubting whether I'll ever learn the comparative benefits of different homebrewing anti-oxygen methods, e.g. keg purging with numerous bursts from a CO2 tank vs. purging via fermentation effluent. Still, I'm grateful for the exchange of ideas and experiences here, even if we can only subjectively measure the results (taste, aroma).

Cheers!

 

[Bilsch]

I'm doubting whether I'll ever learn the comparative benefits of different homebrewing anti-oxygen methods…

First you simply decide that you want to learn it. Then you go ask the people that know.

 

[sibelman]

First you simply decide that you want to learn it. Then you go ask the people that know.

Back in June you wrote, "There is enough CO2 produced from a ferment to purge the serving keg many times over of the oxygen in contains. You simply need to connect from the fermenter to a cleaned, sanitized and dry serving keg then through a fermentation lock. This had been verified by several people who have the proper measuring equipment."

I suppose these are the people that know, and that you have asked them. For a few batches I've been using this method based on assertions like yours that I've found here on HBT. I've seen some arithmetic about the quantity of CO2 produced - also, some arithmetic about successive purges from gas cylinders - along with the inferred oxygen reduction.

But I have not yet been able to find those who "know" by measuring - my preferred way of understanding the world. Perhaps I haven't tried hard enough...

So, my good fellow, could you please offer any tips/links where one might go to learn about the measurements these folks have made?

 

[Bilsch]

So, my good fellow, could you please offer any tips/links where one might go to learn about the measurements these folks have made?

The measurements were made by at least 4 different brewers that possess commercial in-process DO equipment which collects and graphs the data they posted. It was quite clear how well the ferment purge worked.

Unfortunately though on this forum we aren’t allowed to mention the name nor link to the other place that contains said data. The best I can do here is tell you it exists.

 

[madscientist451]

Unfortunately though on this forum we aren’t allowed to mention the name nor link to the other place that contains said data. The best I can do here is tell you it exists.

Since when was it forbidden to put links to sources? If you are worried about it, send it to me on a PM and I'll post it and see what happens.

 

[eric19312]

Hmm I thought I knew where this was posted. Perhaps it is behind the paywall. Anyway when I go to where I thought it was it is same graphs and maths posted here by @doug293cz (and nicely attributed to him over there). I'm with @madscientist451 would be interested to see the report of the measurements that confirm the calculations.

 

[doug293cz]

Since when was it forbidden to put links to sources? If you are worried about it, send it to me on a PM and I'll post it and see what happens.

Hmm I thought I knew where this was posted. Perhaps it is behind the paywall. Anyway when I go to where I thought it was it is same graphs and maths posted here by @doug293cz (and nicely attributed to him over there). I'm with @madscientist451 would be interested to see the report of the measurements that confirm the calculations.

Please contact @Bilsch by PM for information. That's all I will say on this matter. Discussion about why will be deleted.

doug293cz
HBT Moderator