O2 Results from my new O2 meter!

All,

A while back I picked a new disolved O2 meter that reads in ppm just to check the levels of boiled wort to a 90 second pure oxygenated wort and here's what I have found.
It is said that you need from 9 to 11 ppm units of oxygen to promote a healthy yeast growth and a good fermentation of your wort.
I brewed up a Bohemian Lager last week and decided to use my new meter.
After calibrating (and checking it twice), I pulled off a small sample of wort which was boiled for 90 minutes, cooled to 60 degF then checked the O2 level with the new meter. I got an O2 level reading of 1.5ppm. Pretty low!
After stabilizing the temp of the wort and just before pitching, I oxygenated the wort with pure O2 for a timed 90 seconds, then pulled a small sample to be checked with the meter. I got a reading of 17.5 ppm right after aerating. I then waited another hour before pitching and checked it again and got 14.5 ppm!
I pitched the yeast at that time and the lager has been fermenting ever since with a lag time of approx 12 hours.
I do need to say that the yeast (Danish Lager) was grown from 2 wyeast packs in a 2000ml flask and bumped up 3 times then decanted and pitched.
Just thought I'd pass this result along in case somebody is wondering about O2 levels. I now aerate all worts ales or lagers for 30 to 45 seconds.
Hope this helps someone out there......!

Interesting. I'd be curious to see the measured O2 level after a few minutes of shaking the carboy.

sdugre said:

Interesting. I'd be curious to see the measured O2 level after a few minutes of shaking the carboy.

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I can do that...I'm actually brewing right now and am getting ready to start the chill. I'll post my results as soon as I can. I'll measure the levels before and after the shake up! How long do you shake your carboy for?

Good question.

I actually use pure O2 now, but always wondered how effective shaking was when I used to do it. I probably shook it for about a minute and a half or so.

I usually use O2 as well, but I always wondered if it is really necessary. I'll have my results within the hour along with the process I used.

If I understand correctly, the 17.5 ppm was on pure oxygen. It would be better to call that oxygenation because aeration may imply air only.

ok...here's my results and what I did:

I took a sample after chilled to 50 degF and I then ran the wort into the fermenter.
I tested the sample and got a reading of 2.3 ppm.
After all the wort was in the fermenter, I capped it and shook it for 30 seconds, then burped the cap, and repeated for 6 times. Wort temp was 50 degF.
After doing this, I removed the same volume that I tested earlier and then measured the ppm. I recorded a reading of 4.6ppm of O2. Not too good for all that shaking.
Bottom line? I'm going back to injecting pure O2 for 45 seconds and save myself some work. All that shaking for practically nothing.
Hope this helps!

yes...pure O2 in orig post...sorry (corrected)

About how much of a flow do you inect with the pure o2? Vigorous, or just so its bubbling on the surface?

I wonder how much you gain from things like pouring through a funnel and how much from a drill stirrer. I've put off getting the Oxygen kit for almost 2 years now. Might be my next big step up in quality.

Veedo said:

About how much of a flow do you inect with the pure o2? Vigorous, or just so its bubbling on the surface?

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Great question!
I would say that I get an even bubbly flow, not so that the surface is churning,
and I do move my wand in a circular motion while oxygenating. I would call it a medium flow. Maybe I should get some type of flow gauge so that I can measure the rate of flow. Does such a gauge exist? hummmmm......

wottaguy said:

ok...here's my results and what I did:

I took a sample after chilled to 50 degF and I then ran the wort into the fermenter.
After all the wort was in the fermenter, I capped it and shook it for 30 seconds, then burped the cap, and repeated for 6 times. Wort temp was 50 degF.
After doing this, I removed the same volume that I tested earlier and then measured the ppm. I recorded a reading of 4.6ppm of O2. Not too good for all that shaking.
Bottom line? I'm going back to injecting pure O2 for 45 seconds and save myself some work. All that shaking for practically nothing.
Hope this helps!

Click to expand...

Going from 1.5 to 4.6 is a pretty nice increase considering you increase oxygen by 300% without any investment other than an upper body without. Yes it pales in comparison vs pure O2 but your yeasties will appreciate a 300% increase.

Also thanks for posting data. Actual measurements are always welcome.

rhamilton said:

Going from 1.5 to 4.6 is a pretty nice increase considering you increase oxygen by 300% without any investment other than an upper body without. Yes it pales in comparison vs pure O2 but your yeasties will appreciate a 300% increase.

Also thanks for posting data. Actual measurements are always welcome.

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I have since corrected the op. The sample that was tested before the shaking today came in at 2.3 ppm. Sorry for omitting that piece of info.

This is a really cool thread to follow. What is the orifice size of the stone your using?

What are you using to measure and where did you get it? I thought the equipment to check it was like $1000¿

Maybe I should get some type of flow gauge so that I can measure the rate of flow. Does such a gauge exist?

Click to expand...

I have a medical oxygen regulator, something like this:

http://www.ebay.com/itm/H-M-Medical...ltDomain_0&hash=item2303d153a7#ht_1290wt_1152

I set it to 0.5 Lpm. Works great

wottaguy said:

Great question!
I would say that I get an even bubbly flow, not so that the surface is churning,
and I do move my wand in a circular motion while oxygenating. I would call it a medium flow. Maybe I should get some type of flow gauge so that I can measure the rate of flow. Does such a gauge exist? hummmmm......

Click to expand...

Think you could post up a video next time you aerate some wort? I have an 02 setup, but often wondered how much to goose it. The last couple batches I've done i just set it at a mediumish rate and swirl the wand like you, for about a minute. Sounds like I'm close.

sdugre said:

I have a medical oxygen regulator, something like this:

http://www.ebay.com/itm/H-M-Medical...ltDomain_0&hash=item2303d153a7#ht_1290wt_1152

I set it to 0.5 Lpm. Works great

Click to expand...

Say...nice find! Will this fit on one of those red cylinders typically found at home depot or lowes? Thanks for this link! Just what I needed!

pickles said:

This is a really cool thread to follow. What is the orifice size of the stone your using?

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I'm using a 2 micron stone affixed to an acrylic racking cane. The next time I oxygenate a wort, I'll provide some pics.

Mellman said:

What are you using to measure and where did you get it? I thought the equipment to check it was like $1000¿

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I'm using a Milwaukee Portable DO Meter Model: MW600
I picked it up on eBay some time ago and just got around to using it. I happened to get a great deal on mine and couldn't pass it up. (lower price that the one currently listed)

http://www.ebay.com/itm/Milwaukee-M...030?pt=LH_DefaultDomain_0&hash=item3eff2d6386

It works great!

Veedo said:

Think you could post up a video next time you aerate some wort? I have an 02 setup, but often wondered how much to goose it. The last couple batches I've done i just set it at a mediumish rate and swirl the wand like you, for about a minute. Sounds like I'm close.

Click to expand...

I'll keep the video in mind for next time.

Another test that you might consider would be to skip using the wand and instead flood the head space of the fermentor with O2 for a few seconds then shake the fermentor for 30-seconds. Do this flood and shake process a total of two times then measure the results. I read elsewhere recently that this is another good way to oxygenate wort with pure O2 without the wand. I'm curious what level of dissolved O2 this method would achieve.

Thanks for posting your results!

Will this fit on one of those red cylinders typically found at home depot or lowes?

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I don't think so, but someone else might be able to confirm. It fits a standard welding type O2 tank like this:

http://www.ebay.com/itm/20-Cu-Ft-Ox...ultDomain_0&hash=item519eaffa62#ht_4071wt_907

Interesting. I'd love to see more data. I have an irrational (rational?) fear of small sample sizes.

awesome real-world data collection Wottaguy, many thanks! i have one question tho: could you please tell us what size/micron rating your airstone is, maybe even post a link to a pic of the model you use. if i were to duplicate your methods and aerate for the exact same time interval, but with a different airstone, i might get different ppm's of DO and not know it. thanks man!

Great thread. Your numbers seem to be in agreement with the info in "Yeast", the book by Chris White. I struggled for years with consistency and tried many "fixes" before hanging up the kettle out of frustration. Since returning to brewing and purchasing a simple O2 injection system for $60 at my LHBSS, I've had excellent results and now brew with confidence. Soooooo many posts on here related to slow, stuck, problem fermentations are written by posters who "shake and swirl". If only they'd accept the fact that O2 is hugely important for the yeast and shaking and splashing just can't achieve optimal levels in a reasonable amount of time. I recently spoke to a brewmaster at a brewpub who also agreed that O2 content in wort was his primary concern prior to pitching. I'm not sure why so many resist, but resistance is futile!!!

zymurgistic said:

awesome real-world data collection Wottaguy, many thanks! i have one question tho: could you please tell us what size/micron rating your airstone is, maybe even post a link to a pic of the model you use. if i were to duplicate your methods and aerate for the exact same time interval, but with a different airstone, i might get different ppm's of DO and not know it. thanks man!

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Yes...I use a 2 micron stone that can be had here>

http://www.northernbrewer.com/shop/carb-stone-2-micron.html

Very good info!
What size batch?
How vigorous was the bubbling? SS air stone I assume?
Did you get a pressure or flow reading while oxygenating?

Oops, I see you already answered about the stone size.

acidrain said:

Very good info!
What size batch?
How vigorous was the bubbling? SS air stone I assume?
Did you get a pressure or flow reading while oxygenating?

Oops, I see you already answered about the stone size.

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5.2G wort in a 6G Better Bottle
I have no way to check pressure but the bubbling was at a medium rate to not let the surface "churn".
Thanks!

My hero. Science is real. The yeast book has something like 4PPM for shaking too, didn't it?

sdugre said:

I have a medical oxygen regulator, something like this:

http://www.ebay.com/itm/H-M-Medical...ltDomain_0&hash=item2303d153a7#ht_1290wt_1152

I set it to 0.5 Lpm. Works great

Click to expand...

wottaguy said:

Say...nice find! Will this fit on one of those red cylinders typically found at home depot or lowes? Thanks for this link! Just what I needed!

Click to expand...

No, it will not. The one linked to above uses a CGA-540 fitting. That is what a "welding bottle" uses. You can usually get a small tank full of O2 from AirGas or somewhere like that for about $75 or so. It will last you forever compared to the Red Burnz-o-matic tanks.


Medical oxygen tanks use a CGA-870 valve and usually require you to have a prescription to fill. Sometimes you can buy a cheap medical tank on craigslist and swap it for a welding tank at AirGas. I would call and ask them if they would do that first. You don't want to get stuck with a $30 medical tank that you can't get filled.

I played around with an O2 meter a couple years ago and recorded this data:



The measurements shown on that table were the only ones I got from that meter before it wouldn't calibrate anymore. I was pretty disappointed with it. It is the older Milwaukee model that the MW600 replaced. Make sure to calibrate yours often to make sure it's working properly.

I would also like to see readings for the following:

Shaking with the headspace filled with pure oxygen.

Pouring back and forth between 2 buckets.

The siphon sprayer nozzle from Midwest.

Thanks for taking the time to run your tests and posting the results. Greatly appreciated.

dstar26t said:

I played around with an O2 meter a couple years ago and recorded this data:



The measurements shown on that table were the only ones I got from that meter before it wouldn't calibrate anymore. I was pretty disappointed with it. It is the older Milwaukee model that the MW600 replaced. Make sure to calibrate yours often to make sure it's working properly.

Click to expand...

Man those numbers are all over the place.

I forgot to explain that this chart is for 5.25-5.5 gal batches in a 6.5 gallon carboy oxygenated with a .5 micron stone. They are listed chronologically, not by OG or temp or time so you have to study the data for a few minutes. There are too many dependents to graph it out. The last 6 rows of data were for 2 beers with 3 readings taken on each after additional oxygenation.

Very interesting thread thanks for the info.

So I guess 75 seconds is the sweet spot then? From dstars chart it appears thicker worts need up to 90 seconds or longer. Good info I usually go 60 seconds because that is the info that came with my kit but I have had it for like 4 or 5 years maybe that is old info. 60 seconds seems to work.

Any idea what 1 L/min or 3 L/min looks like?

I've posted before about testing wort with a DO meter. My SOP is to give ales 60s full throttle flow with one of the disposable tank/regulator setups, big ales/lagers 90s, and big lagers 120s. If I remember right, I got a PPM of ~15 on a BoPils at about 50F after 120s, and something like 12ppm on an ale at 60s.

One thing to keep in mind is that the meters vary wildly on how reliable they are at reading different things. Some meters don't do well with oxygenated wort but are great with finished beer, some can do both gas and liquid, etc. Knowing your DO meter comes with everyday use-type experience that's just really hard to get outside of a professional brewing setting.

I'm... skeptical... of something reading 300ppm. Maybe dstar meant ppb?

itzkramer said:

I would also like to see readings for the following:

Shaking with the headspace filled with pure oxygen.

Pouring back and forth between 2 buckets.

The siphon sprayer nozzle from Midwest.

Thanks for taking the time to run your tests and posting the results. Greatly appreciated.

Click to expand...

I'd like to see these too. I did read in "Yeast" that air only has 8 ppm or so, making it impossible to get more than 8 with any non-O2 method. Being involved in both aviation and scuba diving, I understand a bit about how gasses diffuse into liquids. Basically the bigger the differential (called partial pressure) the faster the rate of diffusion. So if you target is 8-12 ppm, you can only get to the minimum of your target and it will take a LONG time to get there because of the low partial pressure. This fits with test I read done by White Labs that found 5 minutes of "vigorous" shaking only resulted in 2.7 ppm dissolved oxygen. I believe this is one of the biggest causes of problem fermentations among newer brewers.