CO2 vs Compressed Air

[Kegs&More]

Today I was at my local dive shop getting my CO2 tank re certified. They asked me if I wanted to fill it with air (not nitro) and save money. They claim they fill 1 to 2 tanks a week. I passed, however it peaked my curiosity. Now comes the simple question, Why do we use CO2 and not another gas?

[THE ICEMAN]

To put it very simply. The beer needs the carbonation that CO2 provides & air can spoil beer. There are others that can provide more details.

THE ICEMAN

[cubby_swans]

well, first, and foremost, beer is carbonated naturally during the process of fermentation. Without the co2 providing pressure in the empty space in the keg, the co2 would break out of solution until the co2 pressure in the beer equaled the co2 pressure in the empty keg space (air has VERY little co2) and you'd have flat beer. Most of the gasses in air will not dissolve into solution to provide bubbles.

second, and equally important, is that air (oxygen) oxidizes the beer. Giving it a stale flavor. This is why kegs tapped with 'party pumps' taste bad within about 24 hours.

You could definitely use compressed air to provide dispensing pressure if you were planning a party and were going to kill the keg the same day it was tapped. Then it wouldn't have enough time to go flat or go stale. Using compressed air to provide dispensing pressure would really be no different than using a party pump. Otherwise, if you tried to keep the keg any length of time, you'll have stale flat beer. That dive shop might be filling up tanks for those purposes.

[Kegs&More]

Thanks for the information. Guess the dive shop would rather have their customers diving than drinking quality beer.

[BrewGuru]

I'm curious as to why a dive shop is even filling CO2 tanks, dive shops have very little need for CO2...and you mentioned 'nitro' assuming Nitrogen, which a dive shop would most certianly have on hand and use quite a bit of...

Are you getting CO2 or Nitrogen? Or a blend?

Also, atmospheric mix (air) does not compress to a liquid at standard cylinder pressures, so any 'filling' of a compressed air tank with atmospheric would just be compression.

[Kegs&More]

BrewGuru-The dive shop was not filling tanks with CO2. They were only testing my tank for re certification. I did not fill the tank at the dive shop.

After getting the tank updated I went to a local welding gas supplier to have the tank filled with CO2.

BrewGuru you probably know this but others may not. After so many years your CO2 tanks have to be tested in order for it to be filled. I think most tanks are good for 5 to 8 years. The date of last tested is stamped on the tank. Dive shops will do this for around $10.

[Kpt42]

Its 5 years. My current tank has stamps of 90, 95 and 06.

Did you buy an aluminum tank new or something? Welding shops will swap the tank out and not check the date on the old one...

[cubby_swans]

Did you buy an aluminum tank new or something? Welding shops will swap the tank out and not check the date on the old one...

I have a shiny new steel tank that came with my kegorator. I'd gladly pay $10 when it needs testing rather than swap it out with some beat up cylinder. I've seen some of the ones my neighbor brings home. Sometimes they're a real eye sore. I know they function the same, but I guess I'm particular about my things sometimes.

[Kpt42]

I have a shiny new steel tank that came with my kegorator. I'd gladly pay $10 when it needs testing rather than swap it out with some beat up cylinder. I've seen some of the ones my neighbor brings home. Sometimes they're a real eye sore. I know they function the same, but I guess I'm particular about my things sometimes.

All I've ever had was beat up cylinders. Price was right though. Got the 20 lb tank free.

[Kegs&More]

Chubby, you are like me. I like to show off my work of art. No need to have dull looking equipment dispensing great beer.

[budmanmike2011]

nitrogen

I'm curious as to why a dive shop is even filling CO2 tanks, dive shops have very little need for CO2...and you mentioned 'nitro' assuming Nitrogen, which a dive shop would most certianly have on hand and use quite a bit of...

Are you getting CO2 or Nitrogen? Or a blend?

Also, atmospheric mix (air) does not compress to a liquid at standard cylinder pressures, so any 'filling' of a compressed air tank with atmospheric would just be compression.

what would happen if i was to use nitrogen. i am able to get all i need from a cart at work.

[cubby_swans]

If you were dispensing the keg rapidly, as in a party scenario, then nitrogen would work for push pressure. But nitrogen doesn't dissolve in liquid the same way co2 does. You'd end up with flat beer in a few days at most using straight nitro.

[budmanmike2011]

thank you for the reply I’m new around these parts thanks for the help. I might get a small bottle to use on the weekends for the whole party situation and save the co2 how much does co2 run to be filled these days. this weekend I’m starting my kegerator project.

[cubby_swans]

I think co2 is pretty cheap. I pay $10 to get a 5lb tank filled. A 5lb tank lasts roughly eight 1/2 barrels.