All You Ever Wanted to Know About Oxygenation

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drunkenmonk

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** NOTE: Oxygenation equation updated based on data from dstar26t **

Does it seem like it’s hard to get all the information you need in one place? Since I just came down the learning curve on oxygenation, here’s what I hope is some valuable information.

You need to get oxygen into the wort for good fermentation (I assume most people know this). Splashing and sloshing is probably okay for low to medium gravities, but isn’t sufficient for high gravities, is not a very controlled process, and is hard to do with volumes greater than 5 gallons. If you want control and like high gravity beers (like I do) you need to aerate with oxygen.

General consensus is you need to be north of 8 ppm for standard gravities for medium gravity beers and north of 10-15 ppm for high gravity beers. Good references are Wyeast (http://www.wyeastlab.com/hb_oxygenation.cfm) and Yeast book by White and Zainasheff.

If you’ve read along this far, you’re either ready to upgrade to an oxygenation system or upgrade your current system. A basic system which gets the job done, but isn’t controlled and can be expensive in the long run (by buying disposable, red oxygen canisters) is the William’s Brewing System (http://www.williamsbrewing.com/WILLIAMS-OXYGEN-AERATION-SYSTEM-P699.aspx). I’ve used this system for a number of years and it’s served me well. However, I was never sure how much to open the valve and I always had to have extra tanks on hand never knowing when I might run out.

How do you control the process? Ideally you directly measure oxygen ppm (
http://www.milwaukeetesters.com/MW600.html - $169) and adjust your process from there. Whether or not you opt to buy a meter and take measurements, you can somewhat consistently control oxygen levels from flow rate. Here’s the equation assuming a 0.5 micron stone:

time = 0.113 * (volume / flow rate) * (ppm - 8.1019)

where “time” is oxygenation time in minutes, “ppm” is target parts per million (ppm) oxygenation, “volume” is volume of fermenter in gallons, and “flowrate” is oxygen flow rate in liters per minute (LPM). This is based on a couple data points from White and Zainasheff and a lot of data from dstar26t where they measured dissolved PPM after a known flowrate and aeration time. It's a rough equation which depends on things like wort temperature, wort density, and aeration method (in-line or submerged), but gets you close.

How to not run out of oxygen and control the process? Buy an industrial oxygen tank and regulator. The former is easy. Try any welding supply store or Airgas. Avoid medical oxygen tanks. They’re expensive, hard to find a place to fill, and use the same oxygen just in a fancier tank. The regulator is the tricky part. There’s lots of oxygen regulators out there (mostly medical) including on eBay. The problem is that most have a scale from 1 to 15 LPM. This is too coarse for fractions of LPM needed. The answer is a pediatric oxygen regulator. These are somewhat hard to find, but here’s the one I went with: http://www.respondo2.com/Pediatric_O2_Regulators.html.

It was only $48, has a CGA 540 interface which is what most industrial oxygen tanks have, has a barb output, and has adjustable flow rate in 11 settings with as little as 0.03 LPM.

I hope that helps!! I scrounged the web for a while to both find a full equation for calculating flow rate and a suitable regulator that would have low enough flow rate.

5415.jpg
 
Thanks for doing this. Just ordered the regulator then I'll pick up a nice big oxygen tank.
Always been half assed about oxygenation. Great post. :mug:
 
So if I have a 5 gallon batch of 1.065 gravity wort and my oxygen regulators lowest setting is .25 lpm how long should I leave it in the wort to achieve 10ppm total? 53 seconds?
 
now where to find an inexpensive tank

Got one off Ebay for about $75. I did a lot of research. It's much cheaper to buy your own than buy one from the filling place. Just make sure you have a receipt from a company in the business of selling tanks or the filling places will not fill them.
 
I found a medical oxygen tank with stand and regulator for $30 off Craigslist and it still has gas. I also found a place that will swap medical tanks, as all they do is take off the medical oxygen sticker, all for a $11 swap.
 
I found a medical oxygen tank with stand and regulator for $30 off Craigslist and it still has gas. I also found a place that will swap medical tanks, as all they do is take off the medical oxygen sticker, all for a $11 swap.

What size is the tank? Considering I'm in Texas and just bought an oxygenation system from Midwest I need to get a tank and I wouldn't mind following your process.
 
Alternatively.... for thrifty people.

Shaking or an aquarium pump provides basically perfect aeration for everything other than big beers. 8ppm. It actually is a quite controlled process since you saturate at 8ppm.

An initial aeration followed again in 8 hours provides the perfect levels for most big beers. 8ppm+8ppm = 16ppm
 
It is a 20CF tank that is 25" tall, 4.3" diameter.

If you're having trouble finding some place to swap tanks, don't forget welding supply shops.
 
So if I have a 5 gallon batch of 1.065 gravity wort and my oxygen regulators lowest setting is .25 lpm how long should I leave it in the wort to achieve 10ppm total? 53 seconds?

Duration would be 0.53 minutes = 32 seconds. It's a fairly short duration and you may not get a lot of flow rate accuracy at the lowest end of your regulator. Your best option is to oxygenate for a little longer just to be on the safe side since over oxygenation is generally considered not to be an issue.
 
Alternatively.... for thrifty people.

Shaking or an aquarium pump provides basically perfect aeration for everything other than big beers. 8ppm. It actually is a quite controlled process since you saturate at 8ppm.

An initial aeration followed again in 8 hours provides the perfect levels for most big beers. 8ppm+8ppm = 16ppm

That's an interesting approach. I guess the premise is if the yeast need a total of 16 ppm oxygen, they gobble up the first 8 ppm and then get an additional 8 ppm later. I suppose the same approach could be used with an aeration stone and aquarium pump which also maxes out at 8 ppm. You would have to be able (or willing) to oxygenate in the fermenter with this approach as opposed to in-line oxygenation.
 
Thanks for posting. Ordered a regulator, already have a welding tank. have been using the little red tanks with the williams kit, but aleays run out of o2 and forget to buy a new one.
 
Williams brewing just introduced the a system with the same regulator that I bought: http://www.williamsbrewing.com/BIG-OXYGEN-SYSTEM-P3426C106.aspx

They're charging $180 which includes a tank, regulator, hose, and aeration stone/wand. Since the regulator only runs $48 (http://www.respondo2.com/Pediatric_O2_Regulators.html), the balance is for the tank and wand. You can probably find a cheaper used tank on Craigslist or at your local welding supply shop. Overall, I never buy new tanks (O2 or CO2) because you're going end up swapping them at a welding supply shop to get refills unless you find someone who will refill on the spot or trade you a new tank which is rare.
 
drunkenmonk said:
Williams brewing just introduced the a system with the same regulator that I bought: http://www.williamsbrewing.com/BIG-OXYGEN-SYSTEM-P3426C106.aspx

They're charging $180 which includes a tank, regulator, hose, and aeration stone/wand. Since the regulator only runs $48 (http://www.respondo2.com/Pediatric_O2_Regulators.html), the balance is for the tank and wand. You can probably find a cheaper used tank on Craigslist or at your local welding supply shop. Overall, I never buy new tanks (O2 or CO2) because you're going end up swapping them at a welding supply shop to get refills unless you find someone who will refill on the spot or trade you a new tank which is rare.

That looks like a medical type regulator modified to accommodate a welding cylinder. I think I'm just going to buy a medical cylinder or borrow one for brew days. Refilling it going to be a pain in the rump I think. I haven't figured that part out yet. So sick of the mini bottles from the Home Depot though...
TD
 
Yep, it's a medical regulator, but if you buy one with a CGA 540 interface, it will fit an industrial oxygen tank available at most welding supply stores.
 
You can find cheap, used medical oxygen bottles, but will have a hard time finding a place to fill them and pay a lot more money for refills. The "short answer" is you don't need medical oxygen and tanks for oxygenating beer. You can use industrial oxygen and tanks. That's what the "red cylinders" are if you use a system like Williams Brewing sells and that's what commercial brewers use. If you want the "long answer", do a web search for the difference between medical oxygen tanks and industrial oxygen tanks (hint: it's mostly cleanliness and certification).
 
Interesting post. Where does that equation come from, and how would using a 2 micron sintered stone (instead of 0.5 micron) change the constant? If it's a function of the volume, then a factor of 4 change in the diameter would equate to a difference of 64?
 
Interesting post. Where does that equation come from, and how would using a 2 micron sintered stone (instead of 0.5 micron) change the constant? If it's a function of the volume, then a factor of 4 change in the diameter would equate to a difference of 64?

That's a good question. It's different than force carbonation where you've got a sealed vessel and you're interested in dissolving volumes of C02. It's a function of the size of the oxygen bubbles and how readily they dissolve into the wort. As an extreme example, just putting a hose into the wort and turning the oxygen on wouldn't oxygenate the wort very well as bubbles would come out of the hose, bubble to the surface of the wort, and dissipate into the head space (and no pressure build up like force carbonation since the fermenter is not a sealed container).

0.5 micron is better than 2 micron, I just don't know how much. My equation was based on empirical data where they measured how much volume of oxygen it took saturate the wort with oxygen using a dissolved oxygen meter. You could do the same test with a 0.5 micron stone ... or someone more motivated/smarter than I could analytically derive the result based on solubility.
 
Anyone know what it costs to fill the 20 CF welding type O2 tanks?

$20 or less and it's going to take you a long time to deplete a 20 CF 02 tank; especially compared to how long it would take a typical homebrewer to deplete their CO2 tank.
 
Do you recall if the references you consulted discussed wort temperature? I know that many gasses have dramatically different solubility at varying temps, notably co2. Though I do not know if oxygen, being a smaller molecule than co2, like nitrogen, is less soluable than co2 at comparable temperature differences.

TD
 
TrickyDick said:
Do you recall if the references you consulted discussed wort temperature? I know that many gasses have dramatically different solubility at varying temps, notably co2. Though I do not know if oxygen, being a smaller molecule than co2, like nitrogen, is less soluable than co2 at comparable temperature differences.

TD

No specific reference. I assume around 70F.
 
erikrocks said:
Any idea how the formula would look if I'm using a .5 micron stone?

Time to reach target levels of oxygen would be faster, but not sure how much faster. Results for 2 micron stone were derived empirically.
 
The problem with a 0.5 micron stone compared to a 2 micron stone is it's easier for it to block up. And harder to un block.


The other thing people who use Oxygen need to realize is a lot of the O2 is not staying dissolved in the wort, it gradually bubbles to the surface. Now it may later be reabsorbed, maybe. Or maybe not.

So what I do is after adding Oxygen, I seal up the bucket, and rock it back and forth for a while. This will help dissolve more O2.

What I'm curious about is what happens if you aerate with air by rocking for a minute, then add Oxygen, and rock some more. Does aerating with air make it harder for additional O2 to dissolve, and thus possibly counter productive?
 
I might see if this bears out with a DO meter test. Just picked one up. Also going with a new E type O2 tank and Pedi Regulator with my Williams Brewing SS wand and stone kit.
Hope this helps sort out stubborn lager fermentations for me.

TD
 
When my DO meter worked, this is the data I collected.

oxygenation_data_calculated-43876.bmp


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 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.
 
dstar26t said:
When my DO meter worked, this is the data I collected.

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 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.

Wow, look at the 1.102 OG! Brew strong!

I got all my gear assembled. Going to brew this weekend a cream ale (BM's cream of three crops recipe). Hopefully will be my first time brewing with new system.
Medical E tank and pediatric regulator, SS wand with sintered stone from old setup (Williams brewing), and MW600 oxygen meter.

Got to learn how to use the oxygen meter. Is there a need to stir the wort while oxygenating, or just swirls the wand around a bit, or does this not matter?
Do you let it rest for a period of time after oxygenating before pulling a sample to test, in order to get a representative sample of the DO, or do you pull the sample immediately?

Thanks!

TD
 
I move the wand around a bit at the bottom of the fermenter but I really doubt it makes a difference.

You can pull a sample right away but more importantly, pitch immediately after seeing a reading you like. The DO level will change quickly. The yeast will also uptake the DO quickly. For big beers, I like to re-oxygenate after a few hours. Gone up to 1.115 with good results.

Make sure to read the manual
 
I've been using a 2 micron stone, a medical regulator set at 3 LPM for 30-60 seconds, depending on type, gravity, etc. According to your formula,

time = (0.00265 * ppm * volume) / flowrate

if I want 10ppm, for 5 gallons, at 3 LPM i'd flow for .044 minutes, or 2.65 seconds. That can't be right.
 
Got this via Craigslist for $25, Told the guy if he would deliver to work I'd give him $50.

Turned out, it had 2000psi.
20130920_174128.jpg


My gas place, Holston, just south of Louisville does both swap, and fill while you wait. I'm tickled. :ban:

It came with tank, regulator. and cart. Also a nose hose but I chucked it.

Nipple on the regulator fits beer line, which fits the stone.

pb
 
Any of you guys that are giving up on the red tanks want to sell me your old regulator? Send me a PM if interested.
 
Any of you guys that are giving up on the red tanks want to sell me your old regulator? Send me a PM if interested.

that's very generous of you to refer to that little black knob as a regulator :D it turns the gas on or off, no regulation involved. i'll look in my garage to see if i still have mine, i may have thrown it away, if i find it i'll send you a pm.
 
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