Can CO2 get too old?

[M-P]

So a friend of mine just brought his old kegerator out of storage to give to me. It came with everything except the keg, but after banging around in storage for 4 years it needed some repairs. The fridge door needed some repair work, the faucet needed a part, and the regulator needs a new gauge, but otherwise it is great. It also came with a 5 lb CO2 tank, which happens to still be at least half full. My question is...do I need to release the CO2 that is in there and get a fresh fill or can I just use the 4 year old CO2 that is in there?

 

[lschiavo]

I used the remainder of my cylinder that had been sitting for at least 10 years when I started kegging. I don't think it can go bad.

 

[Grizzlybrew]

I just had a similar discussion with my LHBS guy the other day about a tank I picked up on craigslist. He said the gas shouldn't go bad, but you need to look out for the tank material itself. Steel tanks end up in fabrication shops sometimes and may have other gases put in them, which can affect aroma/"flavor". Also, steel tanks may sweat and rust on the inside, affecting the aroma/"flavor" of the gas also.

 

[lamarguy]

Actually CO2 only gets better with age. It's like beer, all of the heavy "stuff" settles out over time and you get a nice, fluffy, creamy layer of CO2 on top. I believe there are actually CO2 vintages.

Come on guys, don't be silly! CO2 filled at welding shops (and otherwise) is 99.97% pure CO2. It doesn't age, it doesn't go "bad". Steel tanks do not rust on the inside in the presence of CO2 (requires elemental oxygen).

The only known methods for breaking down CO2 into its elemental components are (1) heat it in the presence of a metal catalyst (a la, catalytic converter) or (2) photosynthesis. Neither of these mechanisms are available in your tank.

 

[Grizzlybrew]

Come on guys, don't be silly! CO2 filled at welding shops (and otherwise) is 99.97% pure CO2. It doesn't age, it doesn't go "bad". Steel tanks do not rust on the inside in the presence of CO2 (requires elemental oxygen).

My point, was unless you know the complete history of your tank, you don't know if someone along the line, somebody filled your tank with something it was not intended to hold, including gases that do have aromas and possibly oxygen which could allow rusting to occur.

I'm not saying it is likely, but just that it isn't beyond the realm of possibility.

 

[shortyjacobs]

I just used a CO2 tank with a 1978 hydro test date for my last few kegs. Tasted just fine.

 

[M-P]

Great...thanks for the information.

 

[dae06]

Actually CO2 only gets better with age. It's like beer, all of the heavy "stuff" settles out over time and you get a nice, fluffy, creamy layer of CO2 on top. I believe there are actually CO2 vintages.

Come on guys, don't be silly! CO2 filled at welding shops (and otherwise) is 99.97% pure CO2. It doesn't age, it doesn't go "bad". Steel tanks do not rust on the inside in the presence of CO2 (requires elemental oxygen).

The only known methods for breaking down CO2 into its elemental components are (1) heat it in the presence of a metal catalyst (a la, catalytic converter) or (2) photosynthesis. Neither of these mechanisms are available in your tank.

It's one of those you don't know until you ask. Good question!