Which stone for O2?

I scored an O2 kit from my uncle who is getting out of brewing.

While reading lots of threads about how fast and long to run the O2, I have a couple questions for those of you who use pure O2.

1) Is the regular little stone ok or should I do something like this? I have the little stone, but this is cheap.

2)What rate (without a flowmeter) do I run the O2? Just crack the valve?

3)For mid gravity (1.055 ish) beers, I'm reading 30 to 60 seconds?

4)What kind of care should be taken for sanitation of the stone and tubing, should I have a HEPA filter for the O2?


I'm brewing my first AG Sunday and I'm excited to try this puppy out.

I've never seen anyone use a stone that big, but the small ones work juuuust fine for homebrewers. I give the wort as much oxygen as it can handle(you'll kick up a ton of foam if too much). For the most part, a minute or two of fairly low flow is fine, but higher flow isn't a bad thing. Play with it, you'll see. For a 1.055 beer that's plenty of time. I tend to lean toward the 1.090 - 1.1150 range in my beers, so I give it a bit more, and occasionally a second hit of oxygen within 24 hours or so. HEPA filters aren't ever a bad idea, just in case. Inline ones are super cheap. As far as sanitization, it's business as usual. For cleaning of the stone, drop it in some boiling water for a few minutes. That'll help loosen and remove old wort from the stone's pores, then sanitize as usual to be thorough.

1) you want a stainless stone so you can sanitize it. Those aquarium stones will get all gunked up and nasty.

2/3) Without a dissolved oxygen meter, you're just guessing. I know a lot of people just guess how much they throw in, just like people guess how much yeast they pitch. It'll usually work out alright, but I don't think you'd get the best possible outcome. I would get a dissolved oxygen meter.

4) Autoclave the stainless steel stone. Pure O2 is toxic, so no hepa filter required.

Yeast byproduct formation is very sensitive to the amount of yeast per ml per *P. Yeast make different flavors when they're working aerobically than anaerobically. So too much oxygen will make too much yeast growth which can significantly impair flavor. You only need 8ppm of dissolved O2 for ales and 10ppm for lagers. You can easily get to 8ppm without pure O2, and you can get to 10ppm if you chill your wort to 50 *F first.

Good. I'm going to use the stone I have and play around. See what happens. Thanks!
My wife will be happy that I don't have to splash sticky wort from the brew kettle to the bucket over the kitchen floor.

I would love a dissolved oxygen meter - but until I can acquire one I just use a consistent process with regard to how much I open the valve, how long I run it, the temp of the beer, gravity of the beer, etc. I plan on making a program or at minimum a spreadsheet to try and take some of the guesswork out of oxygenation, but until I get the DO meter all I have is a guess.

However, from the yeast book it says that injecting pure O2 at 1LPM for 60 seconds in a 1.077 wort will produce 9.2ppm of dissolved O2. If you are like me and don't have a flow meter you can still get a good estimate of flow volume by filling a 2L bottle with water and inverting it in a filled sink with the bottle sticking out of the water. Insert the stone in the neck of the 2L under the water and test opening the valve at different levels and time how long it takes to get only air in the bottle. Divide that time by 2 and you have your rough LPM and you'll know how much to open your regulator valve.

RiverCity - That's a cool idea. I hadn't thought of measuring flow like that. A spreadsheet or chart would be a lot better than a WAG. O2 solubility is temperature and gravity dependent. So higher temps and higher gravity mean less O2 will be dissolved. I don't know the specific formulae to figure that out, but I'm sure that info is out there somewhere.