Aerating with Oxygen

[pilotdane]

Any idea how much oxygen (flow rate, time) is a good starting point when using a .5 micron stone in a 5 gallon batch?

 

[Droot]

I don't remember the size of the stone, but the instructions said 50 seconds.

David

 

[Bobby_M]

Pretty much as slow as you can get it to flow for 60 seconds. You want the wort to absorb it, not create a crap load of foam on the top.

 

[SourHopHead]

Oxygenate is a better word to use.

I use 1-2min for a 5gal batch. Sometimes less cuz Star San foams like mad.

 

[pilotdane]

Thanks. I have been doing way too much than. I have been doing 10 minutes at 2 liters/minute and getting quite a head of foam on top. I was not concerned when I used an aquarium stone but with the more efficient .5 micron stone I started to wonder if I could over do it and kill the yeast with too much O2. Good news is 1 minute will use a lot less O2.

Thanks

 

[Bobby_M]

Since you brought up exacting flow rates (I assume you have a medical reg), I run .25 l/m for 60 seconds.

 

[pilotdane]

You are correct it is a medical regulator. I like knowing "how much" O2 is flowing.

I have been reading articles online for several days and one will contradict the other. Here is an interesting one: MB Raines, Ph.D. - Guide to Yeast Culturing for Homebrewers - Maltose Falcons Home Brewing Society (Los Angeles Homebrewing)

Here is a quote from about half way down the article discussing oxygen levels.

"In general, it is difficult for homebrewers to achieve sufficient oxygen levels. The levels of oxygen necessary for optimal fermentation vary depending on the yeast strain. Ale strains usually need between 8-12 part per million (ppm) while lager strains require slightly higher amounts (10-15 ppm). At atmospheric pressure the maximum level of dissolved oxygen in wort is approximately 8 ppm and the saturation level decreases further as the gravity of the wort increases. Thus unless special steps are taken to introduce air or oxygen into the wort, it is difficult for homebrewers to achieve adequate aeration. Recent studies have shown that oxygenation is by far more efficient than aeration. Injection of oxygen through a 2 micron diffusing stone can actually supersaturate the wort with 10-12 ppm of dissolved oxygen being reached in 5 gallons of wort by a single 60 second blast of oxygen!"

 

[dragon99]

Where did you get the regulator? I've been wanting to do oxygen, but I'm not real excited about using the disposable canisters.

 

[dazed]

Oxygenate is a better word to use.

I use 1-2min for a 5gal batch. Sometimes less cuz Star San foams like mad.

Why are you aerating your Star-San?

 

[Bobby_M]

I'm sure he's talking about residual starsan foam in the carboy.

 

[pilotdane]

Where did you get the regulator? I've been wanting to do oxygen, but I'm not real excited about using the disposable canisters.

You can get medical regulators from medical supply houses though some require a doctors prescription to buy/rent cylinders of oxygen. You can also use welding regulators, flow meters and cylinders of gas (oxygen) which do not need a prescription. Just look in the phone book under welding supplies. Just explain to them what you want to do and they could put together the valves and regulator that you need. Even a small to medium sized tank used for welding will last you years home brewing. I don't think I've seen the pressure guage on my O2 move. Personally I like tanks about 2ft tall. They are light enough to easily carry and are the smallest size commonly used welding getting them filled is easy. I just call my welding supplier, leave the empty tank outside and they come and exchange it for a full one.

Another thing I keep around is a 20lb cylinder of CO2. I use it to purge the oxygen out of secondaries when doing two stage fermenting or batch priming. When doing fruit beers I fill the blender with CO2 so I do not aerate the fruit when I puree. It's also handy to fill your bottles with CO2 before filling especially if you want to age them for a long time. Basically since I've got it I squirt CO2 into everything. It's cheap and easy.

 

[SourHopHead]

I'm sure he's talking about residual starsan foam in the carboy.

Yup.. Thanks

 

[greenbirds]

Those of you oxygenating with a stone: Do you just dip the stone down into the carboy and turn on the O2, then time it? Or do you swirl the wort around while bubbling to try to disperse the O2 throughout the wort? Seems like a tiny stone in held in place for just 30-60 seconds would saturate that "pocket" of wort but not do much for the rest.

Of course, I have no idea how oxygen behaves as it goes into solution; for all I know it instantly disperses itself throughout the carboy.

 

[ClaudiusB]

Any idea how much oxygen (flow rate, time) is a good starting point when using a .5 micron stone in a 5 gallon batch?

For my setup the flow rate is set to 300cc/m at 20 PSI, gives me the least amount of foaming.
Above 400 mostly foam.
The oxygenation takes as long as the chilling takes, no fixed time.

I use a standard welding tank and regulator with a Dwyer adjustable flow meter.

Adjustable flow meter.

Cheers,
ClaudiusB

 

[Droot]

I do it a little different. I am a weldor, so O2 is free. I turn more in an "empty" tank than I would use in a year for brewing. SO Its an 80 cubic foot bottle (the smallest one I can take home) and an old regulator with a 3/8" hose barb attached.

I hook the hose to the regulator, the other end to the racking valve on the conical filled with 6 gals of cooled wort. Turn the pressure up, open the racking valve and watch it bubble. If I keep the flow low, it won't foam over the top in 30 seconds. I have tried one minute, two minutes and last time three minutes. Each minute has worked better. So I am up to 3 minutes. With a 1 liter starter, I get a few bubbles in the air lock in 3.5 hours and going fine in 6 hours. I will keep increasing by one minute until I can't see the difference.

This is with no carbonating stone, just a 3/8" hose going in the bottom.

Kinda primitive and crude, but it works and is free.

Co2 is a welding gas too

David


Edit: I just started ranching my own yeast. Or washing and saving. I want to purge the 1 litre flask with 02 to see if it helps the starter. I don't think this matters with a stir plate (which I ordered last week, still not here )

 

[SavageSteve]

I oxygenate for 2 minutes with the gas on at "full", whatever that means for my system, since I don't have a flowmeter. I also swirl the stone around in the wort for the entire 2 minutes, and I get little to no foam.

I suppose I should get a little more precise with my method, since I have no idea how much I'm putting into the wort, but so far, I haven't had any issues.

-Steve

 

[dazed]

I use Medical grade O2 for 1-2 minutes @ 1/8 (.12 on the dial) LPM on a Williams brewing O2 wand (goes straight to the bottom) with very little foaming being produced.

....then I bung the carboy, and rock (shake) it really good to get more of the O2 into solution....seems to work good that way ....

 

[humann_brewing]

For my setup the flow rate is set to 300cc/m at 20 PSI, gives me the least amount of foaming.
Above 400 mostly foam.
The oxygenation takes as long as the chilling takes, no fixed time.

I use a standard welding tank and regulator with a Dwyer adjustable flow meter.

Adjustable flow meter.

Cheers,
ClaudiusB

I am about to buy a oxygen cylinder and regulator but thought the regulator could tell me how much O2 I am putting in. Do I need a flow meter like you have too? Where in the line is that at too?

 

[BioBeing]

....then I bung the carboy, and rock (shake) it really good to get more of the O2 into solution....seems to work good that way ....

Isn't this going to displace you nice pure medical grade oxygen with air (which is 70% nitrogen)?

 

[humann_brewing]

How many 5 gallon batches does a 20CF tank last?

I am just wondering, the fill ups are like a $ apart between 20 and 40 CF tanks but I imagine 20 CF lasts a long time.

 

[dazed]

Isn't this going to displace you nice pure medical grade oxygen with air (which is 70% nitrogen)?

Probably not...since alot of that o2 that came out of the wand tip bubbles at the top, thus mixing with the AIR in the dead space in the carboy...

so in essence there is pure o2 mixed with AIR...so shaking would seem to incorporate some of that back in ...but YMMV....

 

[JKoravos]

I am about to buy a oxygen cylinder and regulator but thought the regulator could tell me how much O2 I am putting in. Do I need a flow meter like you have too? Where in the line is that at too?

Even if you have a flow meter you don't really know how much you are getting in the wort. Not all of the oxygen gets dissolved, and the amount of oxygen that gets dissolved will vary with the temperature of the beer (among other things).

IMO, the key is to be consistent. If you set your secondary regulator to 10PSIG and always use the same stone, you can assume you're getting about the same amount of oxygen being fed into the wort. That's about the best you can do, unless you want to get into theoretical modeling of oxygen absorption in wort.

 

[iceman80403]

I oxygenate very roughly between 30s and 1 min with a 0.5 micron stone at about 2 psig. I turn the pressure up until I just see bubbles rising to the surface then turn it back until I see none so I know all of it is being dissolved. I'm considering drastically reducing the time or even stopping all together and just aerating manually because every single time I oxygenate I get massive continuous blow off for 2 or 3 days that covers the entire fermenter! It's ridiculous and I'm getting tired of cleaning it up!

In any case you can approximate fairly well how much oxygen you are putting in by using the ideal gas law whether or not you are using a gauge that measures volume or pressure as long as you don't have it bubble out of the wort.

 

[JKoravos]

...every single time I oxygenate I get massive continuous blow off for 2 or 3 days that covers the entire fermenter! It's ridiculous and I'm getting tired of cleaning it up!

fermcaps....

 

[Grinder12000]

Seriously though - unless you are making a HUGE beer there is no need to airate a 5 gallon batch if you use a starter.

I believe John Palmer said he never aerates on a 5 gallon batch.

I ALWAYS do but yesterday I brew and did not - pitched my starter and I was fermenting within 3 hours.

 

[matiasek]

I too have recently moved to direct oxygen injection with a 0.5 micron stone. I was under the impression that adequate oxygenation is not necessarily linked to short lag times. I thought that the more your oxygenate the wort the longer lag time you will have due to aerobic respiration lasting longer, before fermentation starts.
So far I have been testing 2.5psi for 60 sec on 5 gal batches and 90 sec for 10 gal batches. How do others scale their oxygenation time with batch size?

 

[Droot]

I always used o2. It seems to cut lag time in half.

I usually get a layer of foam in 6 hours with a big starter and o2.

The last batch I did had a 1.2 litre starter from washed 1272. I just poured the wort from the cube through a strainer in the fermenter to catch the hops. It foamed up so much that I didn't give it any o2. I pitched the yeast at 68*f. It had a layer of foam at 12 hours.

I am still experimenting with dry yeast. Next batch is S-04 with o2.

 

[matiasek]

Here is a neat little experiment on how O2 injection (and dry yeast rehydration) impacts lag time.
[ame=http://www.youtube.com/watch?v=vOrfmzpDmPk&feature=PlayList&p=320A28425782C065&index=0]YouTube - Dry Yeast Experiment[/ame]

 

[stoutaholic]

Before I had a DO meter, I was trying to figure out appropriate oxygenation times, and so contacted Wyeast for more details on their oxygenation experiment. On their website, they show different levels of oxygenation that can be achieved with different methods. They said that 12ppm can be obtained using pure oxygen for 60 seconds, but they didn't specify the flow rate. Greg Doss helpfully responded to my question and said that, for these experiments, they used a flow rate of 3.5 LPM through a 2 micron stone.

So, to oxygenate 5 gallons to 12ppm, you would oxygenate for 60 seconds with a flow rate of 3.5 LPM using a 2 micron stone.

If you don't have a DO meter, your best bet is choose a consistent method of aeration/oxygenation and then vary your pitching rate in order to achieve the desired results (since, in general, oxygenation and pitching rate interact with each other to produce the total amount of yeast growth).

 

[humann_brewing]

I am searching for a regulator and wondering if I could use this possibly.

I realize I would have to switch the tank connection fitting but it has the meter for the l/m.

Or should I just get a standard oxygen regulator for welding and could I buy a gauge that reads in l/m.

Or is it even worth it and just stick with PSI?