Ways to reduce dissolved oxygen in brewing liquor

[zwiller]

I am aware you can boil and also sparge or bubble with gas (nitrogen?) Curious if there are some simple ways to accomplish this. I would rather not boil being a cheapskate on propane Could you hold water under vacuum overnight? We are trying to defeat Hoffman's Law which is what we are up against with DO right? Thanks in advance.

 

[The_Bishop]

Not sure what you're trying to accomplish but prior to fermentation, DO is a good thing. Yeast need oxygen for replication.

 

[ajdelange]

DO is a good thing at one very brief time in the life cycle of a beer and that is just after the yeast are pitched. Any time before or after that O2 is a problem for beer.

I just happened to read a rather lengthy dissertation on brewing Helles (by home brewers) with minimum O2 exposure. They recommended boiling followed by the fasted cooling possible and then dosing at intervals with bisulfite to scavenge any O2 that found its way back in from the air. Needless to say no splashing or vigorous stirring is allowed and all pump connections must be inspected to insure no air is drawn in through a loose clamp. I knew a commerical guy in Yorkshire that did everything under a blanket of CO2.


If you put water under a vacuum overnight when you came back the next day you'd find the vessel empty.

If you sparge with nitrogen I think you will find you are going to need a lot of it. You would also (and this true in any other approach as well) a DO meter to let you know how successful you are, when to add more bisulfite etc.
I think you mean Henry's law.

 

[Spartan1979]

DO is a good thing at one very brief time in the life cycle of a beer and that is just after the yeast are pitched. Any time before or after that O2 is a problem for beer.

I just happened to read a rather lengthy dissertation on brewing Helles (by home brewers) with minimum O2 exposure. They recommended boiling followed by the fasted cooling possible and then dosing at intervals with bisulfite to scavenge any O2 that found its way back in from the air. Needless to say no splashing or vigorous stirring is allowed and all pump connections must be inspected to insure no air is drawn in through a loose clamp. I knew a commerical guy in Yorkshire that did everything under a blanket of CO2.


If you put water under a vacuum overnight when you came back the next day you'd find the vessel empty.

If you sparge with nitrogen I think you will find you are going to need a lot of it. You would also (and this true in any other approach as well) a DO meter to let you know how successful you are, when to add more bisulfite etc.
I think you mean Henry's law.

What did you think about the dissertation? I've read it, and I'm still thinking about it. It would require a lot of changes in my brewing process.

I've always oxygenated my beer immediately before adding the yeast. Does it really matter if the yeast is in there first? This would be an easy thing to change.

 

[GotPushrods]

I also read that a few days ago. It seemed a bit subjective (lots of 'we felt that' type of language) but it definitely got me thinking about my process.

Specifically, how fast does RO water take in oxygen at room temp in the geometry of a standard shaped kettle? I've done a bit of Googling and have yet to find a simple graph vs time. I HAVE always wanted a DO meter!

It did seem like a lot of metabite, but maybe the benefits outweigh any potential side effects from by-products? We're not talking a ton of sulfate here, but I generally despise it. I can't even drink an IPA with high sulfate water that everyone else seems to love.

Sometimes I feel like I worry about DO more than most and it's not discussed enough. I'll be the first to admit that's mostly after fermentation though. Interested to see how this one unfolds.

 

[ajdelange]

What did you think about the dissertation? I've read it, and I'm still thinking about it. It would require a lot of changes in my brewing process.

Pretty close to exactly that. I'd want to taste some of those beers. A lot of Germans have made lot of pretty good beer in violation of the general premise. I remember seeing sinks at Pilsner Urquel aqnd commenting on on article George Fix had written that if that's HSA I want HSA.

I've always oxygenated my beer immediately before adding the yeast. Does it really matter if the yeast is in there first? This would be an easy thing to change.

I'm sure it matters but is one way better than the other? Would have to taste beers done both ways with everything else the same.

 

[mabrungard]

A major concern expressed on the AHA Forum is that the paper does not provide any proof or results. Only recommendations. While I'm interested in moving in the direction of those recommendations based on the premise that oxygen contact with wort has the potential to oxidize the malt components, it would be difficult to accomplish the NoDO goal.

I look forward to the paper's authors presenting analyses showing the presence or absence of those malt components and triangle taste testing that proves they make a difference.

Science Onward!

 

[GotPushrods]

A major concern expressed on the AHA Forum is that the paper does not provide any proof or results.

Do you have a link for this? I did a quick scan and didn't see any relevant looking thread titles in the last few days.

 

[mabrungard]

Its in a thread on German Brewing. It has had a lot of activity in the past couple of days.

 

[techbrau]

A major concern expressed on the AHA Forum is that the paper does not provide any proof or results. Only recommendations. While I'm interested in moving in the direction of those recommendations based on the premise that oxygen contact with wort has the potential to oxidize the malt components, it would be difficult to accomplish the NoDO goal.

I look forward to the paper's authors presenting analyses showing the presence or absence of those malt components and triangle taste testing that proves they make a difference.

Science Onward!

Hi Martin,

I really recommend that you try the low oxygen side by side mini-mash test. Tasting the difference (and witnessing the lighter color with your own eyes) will mean far more to you than a tasting panel p-value.

The test doesn't require any special equipment or ingredients (besides the sodium metabisulfite) and only takes about 2 hours. You can find the tutorial here:

http://forum.germanbrewing.net/viewtopic.php?f=49&t=301

Also, please see my post here:

https://www.homebrewtalk.com/showpost.php?p=7541155&postcount=16

To the OP, in the pdf we talk about various other methods for degassing water that could be employed instead of preboiling. Bubbling CO2 through the water in a packed column is a commonly used method, and I also believe that submersible ultrasonic sonotrodes are a promising approach as well. Check this out:

https://www.hielscher.com/degassing_01.htm

 

[trentm]

Is this the paper that's being discussed: "The role of oxygen in brewing, Technical Summary 3", Tim O’Rourke? and attached.

View attachment The role of oxygen in brewing.pdf

 

[The_Bishop]

That forum requires login to see the post, any chance of a repost here or a synopsis?

Hi Martin,

I really recommend that you try the low oxygen side by side mini-mash test. Tasting the difference (and witnessing the lighter color with your own eyes) will mean far more to you than a tasting panel p-value.

The test doesn't require any special equipment or ingredients (besides the sodium metabisulfite) and only takes about 2 hours. You can find the tutorial here:

http://forum.germanbrewing.net/viewtopic.php?f=49&t=301

Also, please see my post here:

https://www.homebrewtalk.com/showpost.php?p=7541155&postcount=16

To the OP, in the pdf we talk about various other methods for degassing water that could be employed instead of preboiling. Bubbling CO2 through the water in a packed column is a commonly used method, and I also believe that submersible ultrasonic sonotrodes are a promising approach as well. Check this out:

https://www.hielscher.com/degassing_01.htm

 

[techbrau]

The forum is open to the public, you should be able to see it without a login.

 

[mabrungard]

I don't believe that persons that aren't signed up for that forum can see the document. I was able to register and log on to see it.

 

[techbrau]

Hi Martin,

That should be fixed now and should be publicly visible - if it isn't, please let me know.

 

[brewmeister13]

Hi Martin,

I really recommend that you try the low oxygen side by side mini-mash test. Tasting the difference (and witnessing the lighter color with your own eyes) will mean far more to you than a tasting panel p-value.

The test doesn't require any special equipment or ingredients (besides the sodium metabisulfite) and only takes about 2 hours. You can find the tutorial here:

http://forum.germanbrewing.net/viewtopic.php?f=49&t=301

Also, please see my post here:

https://www.homebrewtalk.com/showpost.php?p=7541155&postcount=16

To the OP, in the pdf we talk about various other methods for degassing water that could be employed instead of preboiling. Bubbling CO2 through the water in a packed column is a commonly used method, and I also believe that submersible ultrasonic sonotrodes are a promising approach as well. Check this out:

https://www.hielscher.com/degassing_01.htm

Just a few questions as I'm not fully convinced that de-oxegenating the brewing water would account fully for the results. What type of water were you using and were pH reading taken on all of the test samples?

The reason I ask is, I was thinking about this while driving today and it hit me. If you are using water with bicarbonate, wouldn't preboiling the brewing water remove the hardness and lower the pH of the treated test sample?

I double checked my trusted reference to make sure I wasn't completely mis-remembering the roll of pH on brewing (Kai's page here:http://braukaiser.com/wiki/index.php?title=How_pH_affects_brewing) and sure enough, he did a test on pH and mallard reactions. From what you posted, it doesn't look like you boiled the samples after the test mash, but I'm wondering if a lower pH couldn't account for some of the color difference as well. I also noticed that it talks about tannin extraction being dependent on pH. Could some of the other flavor differences also be due to pH differences? I know hops flavors are very dependent on pH, maybe malt is similar.

I'm not trying to discount your work or your preferred methods, I'm just wondering if something else might be at work here as well.

 

[JohnSand]

I may be over-simplifying. Is your beer suffering from oxygen now?

 

[techbrau]

Just a few questions as I'm not fully convinced that de-oxegenating the brewing water would account fully for the results. What type of water were you using and were pH reading taken on all of the test samples?

Most of the ~10 people who worked on testing these methods are using reverse osmosis water with zero alkalinity. My tap water is pretty close to RO anyway and with a dash of calcium chloride I have negative RA. My carbonate levels are so low that preboiling does nothing to them.

We all are pretty adament about keeping our mash pH at 5.4.

In the pdf, we mention that deoxygenating the water is not enough and active protection is necessary. Take a look at the mini-mash test tutorial here if you're interested. One of the guys who worked on this did a 3 way comparison between a normal mash, a mash with just preboiled water, and a mash with preboiled water and SMB:

http://forum.germanbrewing.net/viewtopic.php?f=49&t=301

 

[ajdelange]

The reason I ask is, I was thinking about this while driving today and it hit me. If you are using water with bicarbonate, wouldn't preboiling the brewing water remove the hardness and lower the pH of the treated test sample?

Boiling carbonaceous water does not decrease the pH unless it is above 8.3. If it is below 8.3 boiling will drive the pH higher (towards 8.3). When natural water picks up carbonate the mechanism involves dissolution of CO2 (from respiring soil bacteria) to form carbonic acid which dissolves limestone. The pH (and hardness and alkalinity) are determined by the partial pressure of CO2. When this water is brought to the surface and boiled the process is reversed. CO2 escapes and chalk precipitates. Again the pH is determined by the CO2 partial pressure. Equilibrium with atmospheric CO2 is at pH 8.3 with hardness and alkalinity both at about 1 mVal. As subterranean CO2 is usually much higher (in mesic regions) pH is usually lower and alkalinity higher. Thus upon boiling pH goes up but hardness and alkalinity goes down. That's why we boil.

 

[ParanoidAndroid]

Wait, so going by this, I am doing a bunch of things wrong?

-I have a 6 gallon pot for 3.25 gallon batches. When I cool, I sit the pot in the sink with ice and stir the wort pretty vigorously till pitching temp. I add ice as needed to the sink. This adds a good bit of O2, which I thought was fine right before pitching yeast.

-When I mash in, I stir up the malts with the water hard to remove clumps, which adds O2.

-I use distilled water from 1 and 2.5 gallon bottles. I just throw the water in there as quick as possible, which adds O2.

-Sometimes I'll filter the wort before going into the fermenter and before pitching. This adds O2.

Has the recommendation always been to aerate right after pitching and not right before? I just read wrong a few years ago?

 

[wobdee]

Yes, pitch before. The yeast take up that O2 very quickly. It only takes a matter of minutes for O2 to start robbing flavor and aroma.