Aeration With O2

[MIWI]

I have the opportunity to be given to me a medical O2 tank and regulator. I read in John Palmer How To Brew book that you purge for one minute at 1 liter/min. It notes to use a airstone. What should be used for a stone or are there other ways other than a stone. I worry about bacteria growth in a stone or is a new stone used for every new batch. Also how big of a stone and can you use a aquarium stone.
Thanks for your time.

 

[Golddiggie]

To oxygenate your wort, before pitching the yeast, you NEED the sintered stone in order to actually infuse the wort. Just putting the O2 into the headspace won't give you much of anything since it's NOT infusing. Get a stone on a stainless wand and connect the regulator up to it via some Bevlex tubing. I've been doing this for a long time now. I adjust the flow level depending on the recipe. Lower ABV batches get about 60 seconds at 1 to 1.5 LPM. Bigger brews get more time and/or more flow to get a solid amount of O2 into the wort for the yeast to use.

Do NOT use an aquarium stone for this. They make stones specifically configured to infuse wort. They are safe for use plus with the correct sized openings.

Get the Yeast book by White and Zainasheff and you'll see why you want to use pure O2 to oxygenate via the sintered stone. Short answer is without the pure O2/stone setup, you're never going to get above 8ppm of O2 in the wort. While that might be OK for low ABV batches, you're doing your brew a disservice (and hindering the yeast) in larger brews.

 

[VikeMan]

What should be used for a stone or are there other ways other than a stone. I worry about bacteria growth in a stone or is a new stone used for every new batch. Also how big of a stone and can you use a aquarium stone.

I recommend a 0.5 Micron sintered stainless steel stone, the kind that can be detached from its wand.

After oxygenating your wort, put it in star san solution for a few seconds, then use more O2 to blow it out. Then detach it from its wand and store it in a little jar of fresh star san solution until next time.

 

[MIWI]

Thank you for the quick response and Infomation. This process will surely beat shacking that glass carboy for five minutes and certainly help the fermentation.

 

[VikeMan]

This process will surely beat shacking that glass carboy for five minutes and certainly help the fermentation.

Yeah, the thing about shaking the wort is that once you reach a level of dissolved O2 at equilibrium with the atmosphere, each additional shake will release as much O2 as it absorbs.

 

[Golddiggie]

IF you go with the stone that can be removed from the wand be absolutely 10000% certain you do NOT touch it with your skin. Oils from your skin will plug the holes in the stone reducing the usable area amount. That's one of the reasons why I have the stone that's fixed to the stainless wand. I cover it with either sanitized paper towel and/or aluminum foil once done using it and set it aside. Zero issues in all the batches I've used it.

I also do push O2 through it both before, and after, using it while it's in the Starsan bucket. That sanitizes it before use, and cleans it after use.

 

[Alex4mula]

I boil my clean wand stone 5 min every time before I use it. That will kill everything I hope.

 

[esdill]

One issue with a medical oxygen tank is that you will need a prescription in order to get it refilled.

 

[FswBG]

Great point from @esdill. About a year ago I was on the hunt for a larger O2 tank instead of throwing money away with those Home Depot red disposable tanks. Medical grade requires a lot of hassle with refills. If it’s free, take it, but I would suggest checking your options before its empty and in need of a fill. Good luck!

 

[IslandLizard]

One issue with a medical oxygen tank is that you will need a prescription in order to get it refilled.

Good point, but there's something to consider...
If that tank is FULL, you'd probably have enough Oxygen for 3 lifetimes of brewing. So refiling it is a non-issue. Just close the valve between uses.

I don't know if "medical tanks" can be refilled without a prescription if not used for medical purposes.
Is it the slim and tall shape that makes them automatically medical? Or the certification?

Anyway, I think I paid $9 for a 40 cu.ft. O2 tank swap. Welders grade steel tank filled with welders grade O2.

 

[VikeMan]

Is it the slim and tall shape that makes them automatically medical? Or the certification?

I'm not sure, but from a practical standpoint, I think it's the regulator and connection.
Medical:

Non-Medical (i.e. welding):

 

[BrewZer]

Since we're talking about tanks -- anybody have any issues getting their industrial/medical tanks hydro'ed?

 

[Golddiggie]

@BrewZer Haven't run out/low on the O2 tank I've had for the past ~9 years so far. I think I still have many, many, many batches left in it. I would just get it swapped for a full one when empty. Let the supplier worry about getting the tank certified.

 

[VikeMan]

@BrewZer I would just get it swapped for a full one when empty. Let the supplier worry about getting the tank certified.

Depending on the supplier, they won't take an out-of-cert tank in a regular exchange, assuming they are paying attention that day. Some will make you you pay for a test and then do the exchange (or fill) only if it passes. Some will charge you for a test and do the exchange, and take their chances on a pass/fail later.

 

[IslandLizard]

Depending on the supplier,

My supplier (Praxair) will swap out of date tanks without a surcharge for hydrotesting.

 

[VikeMan]

My supplier (Praxair) will swap out of date tanks without a surcharge for hydrotesting.

Do the cylinders you are exchanging have Praxair stickers on them? I know that Airgas (around here, anyway) ignores expired certs as long as the cylinder has an Airgas sticker. Sort of a customer loyalty perk.

 

[IslandLizard]

Do the cylinders you are exchanging have Praxair stickers on them? I know that Airgas (around here, anyway) ignores expired certs as long as the cylinder has an Airgas sticker. Sort of a customer loyalty perk.

Yes, the ones I get from them all have a Praxair sticker on them, so future swaps won't be problem.

But I also exchanged an out of date 20# CO2 tank without any questions. That tank looked quite good, though, and the one I got in return was brand new and shiny. They had 6 of those on the lot!

Sadly, at least so far, they won't swap my 15# tank for a 20#, even when offering to pay some extra. I've tried 2 times.
15# is a really odd size... It's a "backup" now, but it's empty and out of date.

 

[Golddiggie]

Last time I had an out of date tank, neither supplier I use (in my area) gave any sh*ts about that. Still got the swap done easily.

Recently swapped out some CO2 tanks that were years out of date at the LHBS and there were no F's given there either. Got filled ones with good dates for just the swap cost.

 

[BrentJ]

Just adding my intel here. I obtained a medical 02 cylinder after a death in the family. I’m kicking myself for not grabbing a couple actually as there was six full ones available. I’ve been using the O2 tank for a couple of years so far. Anyways while swapping a CO2 cylinder at Airgas I inquired about possible future O2 swap. They would not swap without prescription but did say I could exchange empty Medical grade 02 for welding grade O2 cylinder. I guess that’s my option when I run out....