[euge]

So, it sounds like that by not aerating, I've been skipping a pretty substantial step in my brewing - is this correct?

I don't actively aerate anymore.

[rightasrain]

So, it sounds like that by not aerating, I've been skipping a pretty substantial step in my brewing - is this correct?

Since I started aerating with an aquarium air pump. I've been getting explosive fermentations on the 2 batches I've used the pump for. I have heard that it is a critical step.

[rbclay]

so i recently aquired a medical O2 tank. several weeks ago i took it to a local gas supply place, where our club gets a discount i would add, to get it checked and refilled. told them exactly what it was for and that i did not have a scrip for it. they called me last week to say it was ready. i went today to pick it up. they would NOT let me pay for it and take it w/o a prescription/license. others in our club have done the same thing at the same place and not had this issue. their tanks came back with the paint on the top changed from green to orange. mine was still green. i got there 5 minutes before they closed on a friday for a holiday weekend, so needless to say there was not a manager there to speak with. the guy there and i had a very cordial conversation about my intened use, etc. i fully understand his hesitation to let me have it. i plan to deal directly with the manager next week to try to resolve this.

[rightasrain]

so i recently aquired a medical O2 tank. several weeks ago i took it to a local gas supply place, where our club gets a discount i would add, to get it checked and refilled. told them exactly what it was for and that i did not have a scrip for it. they called me last week to say it was ready. i went today to pick it up. they would NOT let me pay for it and take it w/o a prescription/license. others in our club have done the same thing at the same place and not had this issue. their tanks came back with the paint on the top changed from green to orange. mine was still green. i got there 5 minutes before they closed on a friday for a holiday weekend, so needless to say there was not a manager there to speak with. the guy there and i had a very cordial conversation about my intened use, etc. i fully understand his hesitation to let me have it. i plan to deal directly with the manager next week to try to resolve this.

That's not good. At the very least they owe you your tank back without a charge. I would think they could empty it in front of you. It's a real shame because this would cut down on waste. And the medical regulators are perfect for hooking up the filter/stone. I think I am going to sell mine on amazon. Your defenitly entitled to your equipment back. But if they sold you a controlled substance the employees could probably be fined personally on top of fines to the business. In the same way fines can be imposed for selling alcohol to minors. O2 can kill your brain cells but these rules are really nothing more than someone wanted to make money out of licenses and permits to sell oxygen so in other words steal from people who aren't in the best of health. I wonder how they sleep at night.

[euge]

I wondered at first how a medical tank was sold without a prescription to an individual. Oxygen tanks can be had from Harbor Freight or the like and filled at the welding shop.

[oscarvan]

So, it sounds like that by not aerating, I've been skipping a pretty substantial step in my brewing - is this correct?

I don't actively aerate anymore.

I have done pure O2 through a stone, and I have (recently) let the wort pee into the bucket out of the brew kettle, through a short hose, from about a foot up, which makes quite the bubbles.. ...I see no difference in fermentation, other than that I am saving money on O2. YMMV.

[Thirsty_Monk]

I use venturi tube to aerate. Never used O2.
Hight levels of O2 is toxic to yeast.
As someone said. Everything with moderation.

[richardt]

I'm still in the simpler-is-better camp.  Mix-stir or straining and splashing seems fine with me.
And I'm happy with the results I get. 
Just got back from a neighborhood party where 10 couples drained my 5 gallon keg of extra pale ale in under 4 hours.

You will never kill yeast with air, but you can with excess O2. 
On that basis alone, aerating the wort makes more sense than oxygenating the wort.

Ask yourself, how much O2 are you putting into your wort--on the homebrewer level, you aren't even measuring it beyond liters per minute flow rate, if that.  It is just a big abracadabra unless you have personal experience or data to back it up.

[tschmidlin]

The dangers of oxygen toxicity are overstated.  O2 itself is not toxic, although one of the byproducts of respiration, O2- (superoxide) is toxic.  But since there is very little respiration occurring under our typical conditions, healthy yeast should have no problems dealing with the reactive oxygen species generated.  I wouldn't recommend continuous O2, but the level that can be dissolved into the wort prior to pitching won't reach a toxic level.

[James Lorden]

So, it sounds like that by not aerating, I've been skipping a pretty substantial step in my brewing - is this correct?

I believe that proper O2 levels are critical to good tasting beer.  Oxygen is a limiting factor in sterol sythesis and yeast growth.  Boiled wort is devoid of oxygen so, even if using a good pitch of yeast, without oxygen your yeast will not reach the levels needed for the best possible fermentation which can lead to poor attenuation and some unwanted flavor compounds caused by stressed yeast.

Although I now use pure O2 since it takes less time I have had good results from aeration in the past.  One trick with high gravity beer that require lots of oxygen is to run your aquarium pump when you pitch then run it again a while later (like within 12 hours or so).  So long as the yeast are still in their lag phase there shouldn't be much concern in using this method.

[tygo]

One trick with high gravity beer that require lots of oxygen is to run your aquarium pump when you pitch then run it again a while later (like within 12 hours or so).  So long as the yeast are still in their lag phase there shouldn't be much concern in using this method.

I've used this before as well, mostly with really big ales, but also with medium gravity lagers when I'm trying to maximize yeast health for multiple repitches.  I don't overdo it on either oxygenation step, maybe a 1 to 1.5 minutes on the first and another 0.5 - 1 minute on the second.  I've had great results.

[Thirsty_Monk]

The dangers of oxygen toxicity are overstated.  O2 itself is not toxic, although one of the byproducts of respiration, O2- (superoxide) is toxic.  But since there is very little respiration occurring under our typical conditions, healthy yeast should have no problems dealing with the reactive oxygen species generated.  I wouldn't recommend continuous O2, but the level that can be dissolved into the wort prior to pitching won't reach a toxic level.

Thank you Tom.
I aerate with filtered air.
Venturi tube is doing amazing job.
Then I never did a bigger beer then 1080.

[tschmidlin]

Thank you Tom.
I aerate with filtered air.
Venturi tube is doing amazing job.
Then I never did a bigger beer then 1080.

A venturi tube is a great way to go, I'm glad it's working so well for you.

[hopfenundmalz]

I'm still in the simpler-is-better camp.  Mix-stir or straining and splashing seems fine with me.
And I'm happy with the results I get. 
Just got back from a neighborhood party where 10 couples drained my 5 gallon keg of extra pale ale in under 4 hours.

You will never kill yeast with air, but you can with excess O2. 
On that basis alone, aerating the wort makes more sense than oxygenating the wort.

Ask yourself, how much O2 are you putting into your wort--on the homebrewer level, you aren't even measuring it beyond liters per minute flow rate, if that.  It is just a big abracadabra unless you have personal experience or data to back it up.

Sometimes simple is better.  Sometimes making the best beer you can is what you target.

Read pages 75-84 in "Yeast" for the data and advice from the experts.

Personal experience?  The 2 National medal hanging in the basement had O2 injected at 1L/min. for 2+ minutes for 10 gallon batches of Barleywine and Pilsner.  Would those have done as well without the O2?  Who knows.

For some beers, like a bitter or mild,  I just shake the carboy, or use an aquarium pump.  If I want to use power tools, then the mix-stir.
 

[James Lorden]

Personal experience?  The 2 National medal hanging in the basement had O2 injected at 1L/min. for 2+ minutes for 10 gallon batches of Barleywine and Pilsner. 

How are you measuring the 1L/minute?  I use the disposable O2 cans from home depot and I'm looking for some sort of air flow meter.