New to kegging. What size CO2 cylinder should I get?

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ILovePils

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As the title states, I am just buying up ball lock corny kegs in my area. I've got two of them and all the gaskets are fantastic and they hold pressure. I bought a set of gaskets to replace them if they didn't.

I have a 5 gal. fermenter on deck that'll be ready to keg in a couple of days and I'm wondering: What is everyone's go-to cylinder size for CO2? I've heard people say that 10 lbs. is sufficient, and others have said definitely go for 20 lb. cylinders because "the last thing you want to do is run out".

I don't have a kegerator, keezer or anything like that yet, and I plan on, at most, having one pressurized keg and one conditioning until I blow out the first keg, then I'll swap them out, and make another batch.

Is a 10 lb. cylinder enough for what I've got going on and will it support 2 full-time kegs in a kegerator when I get there? I'm not moving fast by any means, I won't have a kegerator for about another year.

Thanks!
 
it takes ~1.5oz's of co2 to carbonate a keg, and 1.23oz's to push it.....how often do you want to swap it?

i just had to refernce this thread that someone helped me out in, with this calculator...

https://www.aqua-calc.com/calculate/volume-to-weight

and fermented beer, due to the co2 produced allready has slightly less then 1 volume.....PSI and temp, might be different, but weight is the ultimate!
 
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it take ~1.5oz's of co2 to carbonate a keg, and 1.23oz's to push it.....how often do you want to swap it?
I guess I'm looking for an answer in terms of how long it takes you to deplete your setup with what you've got going on. That'll put me in the ballpark of what I can reasonably expect to run.
 
that's the question i answered? i carb and push 2 kegs a week a 20lb'r lasts me about 8-10, months but there's always that creepy leak that slips in for a bit.....


i was telling you 5 gallons of co2 weighs, 1.23oz's...which would be what it takes to push it out the tap....and most people like around 2.5 volumes or so, and during fermentation it picks up about .8 volumes, and it will take ~1.5oz's to carb fast or slow......

so a 10lb tank would have 160oz's of co2, (as long as it's actually full, i'd recomend bringing a scale, i got 13lb's with my last 20lb swap...learned my lesson from that when i got home)

being that i like irking him, there's rumor's @doug293cz is the drunk math wizz he can do that for you.....all i get are stickers...... ;)

(and Welcome, not trying to be off putting, i'm just the fool here! :mug: :D)
 
Anecdotally a 5lb tank lasts me several rounds of two 1/6 kegs (5 gal each) in my dual tap kegerator. I’d say I refill it every 4 rounds of 2 kegs if not longer. I’m continually surprised by how long they last. Obviously make sure you check everything for leaks, etc. When you get around to ordering a kegerator it very well may come with one. FWIW I keep a backup just in case.
 
that's the question i answered? i carb and push 2 kegs a week a 20lb'r lasts me about 8-10, months but there's always that creepy leak that slips in for a bit.....


i was telling you 5 gallons of co2 weighs, 1.23oz's...which would be what it takes to push it out the tap....and most people like around 2.5 volumes or so, and during fermentation it picks up about .8 volumes, and it will take ~1.5oz's to carb fast or slow......
I had thought part of your reply was an ad for some reason and the full reply did not show until I quoted it and I removed the "ad" part, sorry about that!

I plan to share beer from the corny keg I have, but I don't brew very often. I'm certainly not anywhere near pushing 2 kegs a week. By your math, I believe I could make a 5 lb cylinder last for about 28 kegs, being conservative. That's a lot of damn beer! I guess I could start with a 5 lb'r and always get an extra if I needed it. This is great info, thank you! Also, if my math seems off, please let me know.
 
I had thought part of your reply was an ad for some reason and the full reply did not show until I quoted it and I removed the "ad" part, sorry about that!

I plan to share beer from the corny keg I have, but I don't brew very often. I'm certainly not anywhere near pushing 2 kegs a week. By your math, I believe I could make a 5 lb cylinder last for about 28 kegs, being conservative. That's a lot of damn beer! I guess I could start with a 5 lb'r and always get an extra if I needed it. This is great info, thank you! Also, if my math seems off, please let me know.


@doug293cz never mind, we got a spunky new kid, figured out for themselves.....yeah that's what i get too.....~28 little leaks do work there way in though, gotta be carefull....and 5lb'rs are what most people use, i really only upgraded to my 20lb'r when i was going through a 5lb'r every week thinking "that's just the way it is".....until i realized i had a massive leak problem......


(i keep my tank on a digital postal scale now, just caught a leak after i only lost an ounce....)
 
5 lbs cylinder gets me 8-10 corny kegs. Thats 6 months for me.. Its a good place to start. Of coarse I would trade it for a 10 lbs.


i'd check your system for leaks.....that's 10 oz's of co2 a keg, their etiehr shorting you on a swap/fill, or that be some damn carbonated stuff.....

oh and @ILovePils there is purging i forgot...but not too bad.....
 
Practically I'd say buy the biggest tank you can afford but if your kegerator/keezer requires you to keep the CO2 tank inside it then the biggest tank you can fit in there. (Some kegerators don't have a port to run the CO2 line to the outside.)

The cost difference to fill tanks is not that much. You can usually fill a 10lb tank for a few dollars more than a 5lb tank. In the short term you'll pay way more for a larger tank but over the long term you'll save money on fills and time/gas going to get them filled.

I have a 5lb tank that came with my two tap kegerator that I use because it was free to me (the kegerator was left in the house when I bought it) but I rarely fill it so we are not talking about a massive amount of money unless you start burning through kegs quickly and/or start using CO2 a lot in your brewing to move liquid.
 
CO2 a lot in your brewing to move liquid.

which still can be calculated with that awesome calc... @yoop89 pointed me too......still can calculate the weight of co2 you'll need.....i'm trying to remember where that graph of how many purges are required to purge a keg at different psi's.....anyone else?
 
I would check around your area to see what refills or swaps cost. If locations in your area only swap, be prepared to lose the shiny new tank you just bought. I have 20 lb cylinders and exchange them at a local welding supply company. I give them an empty, they give me a full cylinder, never the same one and the condition of each cylinder varies. I’m not concerned about the cosmetics. They also take care of the hydro recertifications as long as it’s one of their cylinders. They have 5, 10 and 20 pounders available to exchange, but the cost per pound is a much better deal for the 20. At this particular place, a 10 pounder is only a couple bucks less than a 20. Fire extinguisher companies will sometimes do refills, and depending on the marijuana situation in your state, some dispensaries and or green houses will offer refills, but the hydro certification still needs to be current.
 
I’m not concerned about the cosmetics.

they even gave me a discount when i got a swap extremly ugly one....but the last one came from them too?

I give them an empty, they give me a full cylinder,

do you double check it at home on a scale to the TW stamp? i get shorted at least 2 lb's every time, last time pissed me off, and i'm bringing my scale with me to weigh them all to at least get the one closest to 20lb's.....
 
do you double check it at home on a scale to the TW stamp? i get shorted at least 2 lb's every time,
I’ve never checked and guess I don’t have any reason to not trust them. I exchanged one a while back and just threw it on my scale and it’s only a couple pounds short, but I’ve already carbed a few kegs and dispensed a few others as well as some purging operations, so I’d say it was pretty close when I got it.
 
I’ve never checked and guess I don’t have any reason to not trust them. I exchanged one a while back and just threw it on my scale and it’s only a couple pounds short, but I’ve already carbed a few kegs and dispensed a few others as well as some purging operations, so I’d say it was pretty close when I got it.


so probasbly couple pounds short at 2. oz's a keg, 16oz's a pound..probably like the 18lb's kegs i get, but the last cut me deep at 13lb's.....

if you check em more often.....



and i was looking for a song with the lyrics, "cuts like a knife".....but this is what i found, lol

uassmine, not that i'm saying that....just i'm curious....how often they short people on weight.....don't know if it matters they'd probably just charge more, but then it'd be straight....
 
which still can be calculated with that awesome calc... @yoop89 pointed me too......still can calculate the weight of co2 you'll need.....i'm trying to remember where that graph of how many purges are required to purge a keg at different psi's.....anyone else?
ppm O2 after purge table.png
ppm O2 after purge chart.png


Purging "empty" kegs, or only partially filled kegs, is very wasteful of CO2, as the total amount of CO2 required to reach a given O2 level is proportional to the headspace volume in the keg. If you can capture fermentation CO2 to do the purging, then you don't have to use CO2 that you paid for.

Brew on :mug:
 
can you modify that to go to 50psi!....exactly how much pain do i have to actually go through watching the scale go down while purging...? oh hell i do it if i'm sober in the morning...

but in my drunkin stupor now, what would be worse, whaitng and purging....until you get the right weight of co2, or purging upfornt...like how long does co2 take to dissolve vs o2?
 
As said before, the bigger tank sizes need fewer refills/swaps, while the price difference between refilling/swapping a 5# or 10# tank maybe only a few bucks. Even more so between 10# and 20#s. CO2 is a cheap commodity, it's the handling and refilling that demands time and labor.
I now pay $25 for a 20# swap, aluminum for aluminum. A 10# swap would run around $20 if they even have them, a 5# around $15.
So 20# of CO2 using 5# tanks will run $60, plus 4 trips.

Now a leak somewhere will empty a larger tank too, with time, so there is more to lose.
Also as mentioned, make sure the tank fits inside your future kegerator/keezer if you don't want or can't keep it outside of it.
 
I have to 5 gallon ones. If one goes out I always have a spare filled and ready
 
IMO, every home brewery/bar needs at least two cylinders. You don't want to run out in the middle of a party, or in the middle of purging, or in the middle of a closed fermenter to keg transfer, etc. I have 4.
 
I second checking swap prices. If cannabis is legal around you grow shops are the place for 20# bottles. I pay around $10 for an exchange, less than a third of welding supply shops in my area. Also less than a 5# swap. They usually sell the bottles for cheaper too, but dont offer a title if that's important to you. I say 20# if the space allows, I have several.
 
I've found a cannabis grow supply place near me that does 20# CO2 exchange for $11. They will exchange cylinders that are out of date without any extra cost (they never check the date). Their supply seems to sort of rotate among the three local welding gas companies.
 
I second checking swap prices. If cannabis is legal around you grow shops are the place for 20# bottles. I pay around $10 for an exchange, less than a third of welding supply shops in my area. Also less than a 5# swap. They usually sell the bottles for cheaper too, but dont offer a title if that's important to you. I say 20# if the space allows, I have several.

What do you mean by "don't offer a title"? Don't tell them you're a homebrewer? Because I feel like whenever you say "homebrew" to any supplier, it's justification for them price gouging.
 
Here’s a pic of the 5lb tank that came with my kegerator and the 25lb from my local grow shop. Definitely take space into account.
Growers use CO2 to help boost their veg stage, and their regulators are configured a bit differently. When you get a regulator I HIGHLY recommend choosing one with two valves and a volume gauge. This will allow you to run different kinds of beers at different CO2 levels (or use a bottling attachment), and also allow you to see what the tank has left.
Another fill-up option you can check on is a local paintball shop if you have one. We have a paintball/air soft store in town, and I get my tanks filled there often too.
94444772-2FF1-4998-A29A-EF5EC82032CD.jpeg
 
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IMO, every home brewery/bar needs at least two cylinders. You don't want to run out in the middle of a party, or in the middle of purging, or in the middle of a closed fermenter to keg transfer, etc. I have 4.
Actually put two kegs in this week and just checked them this am and was out of Co2. Glad I had my spare lol
 
What do you mean by "don't offer a title"? Don't tell them you're a homebrewer? Because I feel like whenever you say "homebrew" to any supplier, it's justification for them price gouging.
Welding shops typically give a title, showing proof of ownership just like a vehicle. I have them for my torch and welding cylinders. I have never had to show them for any reason, but thought it was worth mentioning.
 
Practically I'd say buy the biggest tank you can afford but if your kegerator/keezer requires you to keep the CO2 tank inside it then the biggest tank you can fit in there. (Some kegerators don't have a port to run the CO2 line to the outside.)

The cost difference to fill tanks is not that much. You can usually fill a 10lb tank for a few dollars more than a 5lb tank. In the short term you'll pay way more for a larger tank but over the long term you'll save money on fills and time/gas going to get them filled.

I have a 5lb tank that came with my two tap kegerator that I use because it was free to me (the kegerator was left in the house when I bought it) but I rarely fill it so we are not talking about a massive amount of money unless you start burning through kegs quickly and/or start using CO2 a lot in your brewing to move liquid.


What @mashpaddled said. I just upgraded from a 5 lb to a 20 lb tank. $22 to fill the 5 pounder. $34 to fill the 20 pounder. Said differently, $54 cheaper for the same amount of CO2.
 
can you modify that to go to 50psi!....exactly how much pain do i have to actually go through watching the scale go down while purging...? oh hell i do it if i'm sober in the morning...

but in my drunkin stupor now, what would be worse, whaitng and purging....until you get the right weight of co2, or purging upfornt...like how long does co2 take to dissolve vs o2?
I keep a keg full of sanitizer. When I am ready to keg I just push the sanitizer into the next keg (or 2 in my case) in line with co2. You then have a fully purged keg (s), in one pass, and save a lot of gas.
 
I second checking what is available in your area. Might turn out that the math/convenience of swapping vs. purchasing/filling/refilling isn't worth it.

I seem to recall reading somewhere that if you're going to refill, you should chill your cylinder as it will allow a better fill? Is that true?
 
Look around and see what you have available locally to you. Where I am, there's tons of welding supply places, hydroponics stores, and Craigslist/online marketplace sales. Look around enough and find a 20 lb tank and call around to see what swap out prices are. My local hydroponics store swaps out 20 lb aluminum CO2 tanks they get supplied through Airgas for $23, no questions asked, not even looking at any markings. What's better than 1 tank? 2 tanks! Do you ever want to run out of CO2 when you need it?

My first beginner kegging kit from Morebeer came with a 5lb tank. I've never refilled it since it first emptied because it's cheaper to refill my 20 lb tanks. It's probably something I'll sell or give to a friend just starting.
 
i think @ILovePils wanted to know how many kegs he can carb and push?
It's probably something I'll sell or give to a friend just starting.


hear that Ilovepils...free 5lb tank, you just pay shipping! ;)

(and to everyone saying two tanks are better then one, a scale is cheaper! and when the high pressure gauge starts to drop, it's time to swap! but you still have two three days left....)
 
i think @ILovePils wanted to know how many kegs he can carb and push?



hear that Ilovepils...free 5lb tank, you just pay shipping! ;)

(and to everyone saying two tanks are better then one, a scale is cheaper! and when the high pressure gauge starts to drop, it's time to swap! but you still have two three days left....)

Tomayto/tomahto. The title claimed new to kegging and inquired on suggestions of CO2 tank size. I would never recommend a 5 or 10 lb tank to anyone wanting to use CO2 for homebrewing or kegging in my locality, hence the given reasons I stated for searching for a 20 lb one and using it. If you want to talk about prices, I've acquired (3) 20 lb tanks for $90 total. Two of them on separate Craigslist ads for $60 and $30 respectively. And the third tank was free that came with a kegerator also on Craigslist. (threw away the fridge and kept the tank, regulator, coupler, tap) Sure, prices for used stuff and availability will vary depending on where you live, but if you're not in a hurry, look into local deals and take advantage of them.

To answer the OP's follow up question of if a 10lb tank will support a kegerator in the future, yes it will. A 10lb tank will push and carb 15 to 20 five gallon kegs of beer without any line leaks or CO2 purging for other homebrewing related activities.
 
I do purges, etc with my main 10lb tank, so it's not an exact science, but I think I get roughly one keg per pound of C02, carbed and dispensed, including all extra activities as well.
Maybe I've got a small leak somewhere in the distributor or kegs somewhere, not sure.
I don't think you should realistically expect to get 28 kegs out of a five pounder though even if the math says that what it is.
The larger the tank, the cheaper the Co2. So the answer to the original question, if it is meant to stay stationary, is as big a tank as you can afford/fit.
 
then how the hell am i getting 75 kegs carbed and pushed with a 20lb, filled only with 18lb's?

let me pull up some pics...
co2tanklasts.jpg


you can see how much i brew, and a 20lb'r only filled to 18lb's serves that much for me for 10 months, and that's before i had my current scale and only caught a leak after i allready lost 2 lb's to it....now i can catch after only an ounce! whew who!

just looked at my finacial records for 2017, i swapped a tank for $27 on Jan 10th 2017, and again on Oct 16th 2017......and like i said i'm prone to leaks with my ghetto setup.....think i lost 2-3lb's acording to cheap spring load bathroom scale i was keeping it on.....now i got a nice digital one....

and in case you're curious what drinking that much costs, :D that unassigned one is the bottle of fortified wine i felt like buying.....

cheapdrinkinglol.jpg
 
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I use a 20lb on the kegerator (4 corny kegs, 3 beer, one fizzy water). I also have a 5lb for purging / pushing / backup etc.
I have a fill kit so I can get a relatively cheap 20lb fill, and then fill the 5lb from the 20lb.
Kit pays for itself after the first 5lb fill. Fizzy water needs higher pressure (40+ psi) so uses more CO2.
 
It depends on where you get your CO2. We only have swaps now, and they don't carry 10# cylinders so I couldn't swap that one out any longer. So I had a 10# that was pretty useless. They do swap 5# and 20#, although with the "hazardous" fee, which I think was $10/tank, they are pretty close in price. If I remember correctly, the 5# was $22 or so, and the 20# was $35ish.
 
can you modify that to go to 50psi!....exactly how much pain do i have to actually go through watching the scale go down while purging...? oh hell i do it if i'm sober in the morning...

but in my drunkin stupor now, what would be worse, whaitng and purging....until you get the right weight of co2, or purging upfornt...like how long does co2 take to dissolve vs o2?
ppm O2 after purge table-3.png
ppm O2 after purge chart-3.png


You can't purge by weight. After the first few purge cycles, the weight change between cycles is infinitesimal.

You really don't need to wait, after pressurizing with CO2, before venting. The CO2 rushing into the keg will mix up the headspace almost instantly. If you wait on the fill cycle until the noise stops, then mixing will be complete, and you can vent immediately. Even if mixing isn't quite complete, you are more likely to have higher CO2 concentration(lower O2) in the lower portion of the headspace, and the upper portion, from which you vent, would have the higher O2 concentration.

Brew on :mug:
 
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the weight change between cycles is infinitesimal.


MF'r i purge and cry because it costs me 1/2-1 oz, but i've been doing it 6-7 times, but sometimes i cry harder thus the wide variance...do i need to worry that much...and yeah i got my tank on a scale that, if i put a plastic measuring cup that weighs 24grams (from a gram scale) it goes up .8 ounces.....co2 leaks terrify me!

but purging, damn i could carb the keg with what i'm burning right now.....not even sure if i give a f about oxidation that much.....

thanks for the chart, so if i only do it 4 times at 50psi, it's like about 7 times at 20psi? 3 times wouldn't even hurt the scale...i see that scale drop about.0.1oz a blow.....

edit: being that my little oxygen tank is only 1.x oz's and co2 is a luid at reasonable pressure? you talking about the o2 or the co2? because i assure you 1oz is A LOT! :D :mug:
 
MF'r i purge and cry because it costs me 1/2-1 oz, but i've been doing it 6-7 times, but sometimes i cry harder thus the wide variance...do i need to worry that much...and yeah i got my tank on a scale that, if i put a plastic measuring cup that weighs 24grams (from a gram scale) it goes up .8 ounces.....co2 leaks terrify me!

but purging, damn i could carb the keg with what i'm burning right now.....not even sure if i give a f about oxidation that much.....

thanks for the chart, so if i only do it 4 times at 50psi, it's like about 7 times at 20psi? 3 times wouldn't even hurt the scale...i see that scale drop about.0.1oz a blow.....

edit: being that my little oxygen tank is only 1.x oz's and co2 is a luid at reasonable pressure? you talking about the o2 or the co2? because i assure you 1oz is A LOT! :D :mug:
You can easily weigh the amount of CO2 entering the headspace during the pressurize portion of the purge cycle. What you cannot do is determine the amount of residual O2 in the headspace by weight. Purging is all about getting the residual O2 down to a level acceptable to you.

If you turn over kegs quickly, and don't do NEIPA's, then you will be less affected by oxidation than someone who's kegs last months before kicking, or someone who brews extremely oxidation sensitive styles. So, you can probably tolerate significantly more O2 in the headspace, and not need to purge as much.

Brew on :mug:
 
You can easily weigh the amount of CO2 entering the headspace during the pressurize portion of the purge cycle. What you cannot do is determine the amount of residual O2 in the headspace by weight. Purging is all about getting the residual O2 down to a level acceptable to you.

If you turn over kegs quickly, and don't do NEIPA's, then you will be less affected by oxidation than someone who's kegs last months before kicking, or someone who brews extremely oxidation sensitive styles. So, you can probably tolerate significantly more O2 in the headspace, and not need to purge as much.

Brew on :mug:


so like i drink a keg in 4 days, and try to keep 6 full....so just like two purges would work? i only use like 1.5oz of hops in my 10 gallon batches......sometimes 2...

i do apreciate the effort the chart that "goes to 50", lol....next empty keg i get without a sticker allready i'll dedicate the one i have to slap on it to you! :)
 
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