What grade O2 to order?

[Darel Matthews]

Looking to experiment with supplementing my current compressed air wort aeration with O2. What grade of O2 do I need to order from the gas co? I understand medical grade is an O2/N2 mix or something like that. Any other recommendations?
Thanks,
Darel

[gabewilson50]

Depending on what your existing setup looks like, you may be able to use industrial O2. Some oxygenation stations have sterile filters and liquid separators built in, since air from a compressor is not exactly the most sterile source of O2.

[Darel Matthews]

I'm starting from scratch - O2 tank to a sterile air filter attached nearly directly to an airstone. So as long as I have the sterile filter I can use simple industrial O2?

[Moonlight]

My gas guy told me that medical grade is the same as normal oxygen, except that the cylinders themselves are more hygenically treated. I use normal oxygen.

[wiredgourmet]

I use industrial and pass it through a sterile filter. Never had a hint of a problem. I hate to talk about what I've heard and don't actually know, but this could be relevant: I've heard that medical O2 sometimes contains a fungicide. Well, yeast and fungicides, you get the picture... I honestly don't know if it's true, but it's something I would definitely ask about I were to work with a medical supplier.

[matt]

We buy "food Grade" 02. 99.9% purity.
Pure O2 is a sterilant(toxic) and not much can live in it. (not much need for a sterile filter)What you need to watch for is contaminants, water, oil, CO, etc.

[Ted Briggs]

What you want is GMP grade. It stands for Good Manufacturing Process is is certified against contamination. It is a grade below medical grade but above standard industrial grade and is considered "food grade"

[Laughing Dog]

O2

We use Aviators gas whis is a pure Dry O2, medical grade of O2 can contain some moisture content.
aviators gas has to be dry as most LOX tanks are outside the heated presure cockpit or cabin of an aircraft and the moisture would freeze creating issues with the delivery system.

Laughing Dog

[Darel Matthews]

Excellent, thanks guys!

[burcher]

industrial/welding?

what about welding oxygen? I get CO2 from a gas supply place and it's easy for me to get their O2. I'm guessing it's the same story and these guys told me the gas is basically the same just a different process for the container/tank. Anyone do this?

[dick murton]

Just ask for food grade, oil free. Medical is overkill, and the suppliers might not want to sell it to you for risk of contamination due to back flow.

Ideally you should pass it through a gas sterilising filter, typically 0,1 micron before use, and a non return valve just prior to tthe injection point. The gas supply system from the gas filter through to injection point should be sterilisable with rust and oil free steam. Realistically, keep all the pipes,hoses and injection system such as a sinter really clean, and you probably will be OK,

[TL Services]

Sound advice all-round on 'food grade' O2 - the other point with this is you're going to be getting something that has passed food use and has traceability for that, so in this litigation-obsessed world your back's covered!

[Alex T]

Hey,

But if you already have compressed air hooked up, why go to O2? We have recently (in the past couple of years that is) swapped all of our O2 injections over to compressed air (wort, 2 x props and 2 x carlsberg flasks) - cheaper and much easier to not have O2 cylinders around the place.

For compressed air, we typically go particle filter, carbon filter, sterile filter, and then another sterile filter which gets steamed in place (or have an autoclavable filter you put in). Works good for us. If your DO is a bit low with air, try collecting wort with a slight amount of overpressure (0.5bar for example).

But hey, I thnk you have already decided to go with O2, so maybe my words are wasted......

Alex

[TL Services]

Achieving wort DO2 levels of around 10mg/l. is possible with air, but going much above that it is more effective to change to oxygen.

Ensuring consistency is critical for good fermentation, helping flavor-matching from brew-to-brew and avoiding the fermentation cycle being slow or getting stuck.

[beerking1]

I spoke with my gas guy (company supplies both welding gas and medical gas, as well as everything in between), and he tells me there are 2 primary differences between standard O2 and medical O2:
1. Medical O2 comes from the same source, but is tested for purity, standard is not tested.
2. Fittings for medical O2 (regulator, guages, etc) are stainless. Standard is brass.
He also told me that the owner had to give us a special dispensation when we ordered medical grade because technically his license only allows him to sell medical grade to an MD.