Gas Cylinder Sizes | Capacity, Pressure and Optimization

May 19, 2022
Gas Cylinder Sizes | Capacity, Pressure and Optimization

Whether you’ve had a home bar or garage bar for some time or are new altogether to the world of kegerators, chances are that you have a rather rudimentary understanding of gas cylinder sizing and how that relates to your setup.  That probably translates into “big cylinder, more gas, little cylinder, less gas.”  Although, completely correct, it sometimes helps to have a more sophisticated appreciation of how gas cylinder sizes factor in, so you don’t find yourself the unfortunate victim of having no gas to push your beer and a crowd of thirsty friends who now wish they’d made other plans than hanging out with the guy who has beer he can’t pour.  

If you have your own setup or bought a kegerator online, more than likely it has a five-pound gas cylinder.   For a lot of folks, that size cylinder will be perfect, being able to get maybe five to seven half barrel kegs in before having to get a refill.  For me however, it’s an hour round trip to get a cylinder filled, and, if I’m having to get beer gas for my nitro beers (80/20 nitrogen, CO2 mix) I often have to drop it off to be mixed and come back, so we’re now talking two hours of my life gone, up in the air like the beer gas I’m pushing!  Below I walk through a variety of gas cylinder sizes and how they translate to your setup.

Rule of Thumb:  Generally speaking, you can assume that dispensing a half-barrel keg of beer will take about one pound of CO2.

Home Draft Setup | A Guide to Gas Cylinder Sizes

A variety of factors come into play when it comes to how long your gas cylinder is going to last. First and foremost, ambient temperature and whether you store your gas cylinder inside or outside of your kegerator will contribute to the number of kegs you’ll be able to push.  When gas is cold it contracts and when it’s warm it expands; I’m a fan of storing my cylinders outside of my kegerator so as to be able to extract just a bit more "umph" than I’d be otherwise able to.  If you’ve got a small cylinder, this particular detail is going to be THAT much more important.  

Another factor affecting the number of kegs you’ll be able to get out of a cylinder is how cold you keep your beer; the colder the beer, the more CO2 it absorbs.  Understanding that there are several variables at play, the table below provides a relative idea of what you can expect relating to the number of half barrel kegs you can push for normal sized cylinders which many folks use in their setups.  

Dimensions and Pours of Various Gas Cylinder Sizes

Gas Cylinder Sizes

Maximizing Your Pours | Carbonation

As mentioned above, optimizing your temperature to carbonization ratio is important and there’s more than an art to homing in on the “sweet spot” – there’s a science to it. Given that significant amounts of research have gone into understanding the saturation of gases into liquids, we can rather easily plot out the specifics relating to temperature versus pressure and how that translates into your specific setup.  

For me this is easy as I keep a Bluetooth Temperature Sensor inside my kegerator; with this real time detail, I know that on average the kegerator runs about 34 degrees Fahrenheit.  Based on the chart below, to run optimally (for most beers) I should have my pressure set to somewhere between 7 to 10 PSI.  For some folks, this level of detail won’t matter and you’ll continue on oblivious…but anything worth doing in life is worth doing well.  If you’ve invested the capital in having beer on draft at home, it seems fitting that you enjoy it to the fullest.

Carbon Optimization Chart, how to determine gas cylinder sizes

Carbonation Optimization Chart

How Big is Mine, You Ask? It’s Pretty Big

gas cylinder sizes, bourboneur

As I mentioned above, I was spending more time that I’d like having to fill my gas cylinders.  In the past couple weeks, I finally decided however that it was time to up my game to gain back some time that I’d otherwise spend going back-and-forth to a local welding supply store where frankly, I felt I was never dirty enough or important enough with my dinky (by their standards) cylinders to get good service.  To their surprise, I went in and bought two S cylinders, one each of food grade carbon dioxide and beer gas (for my nitro setup).  These cylinders put my prior five-pound cylinders to shame and by my count should yield around 150 kegs each.  I go through maybe a dozen to 15 kegs in any given year in my garage bar with a single tap, so my hope is to not have to need gas for the foreseeable future. Below I’ll talk about how I pieced together this new setup as S cylinders aren’t exactly easy to hide and it may inspire some of you to do the same.

Scaling UP | Garage Bar Gasification  

Going with larger cylinders comes with its own unique challenges, mainly being where to store something that’s nearly five feet in height.  In my situation, I was able to find some space within a fenced in area right beside the back of my garage.  With the location set, I bought two lengths of 100 feet worth of gas line (one set being red for CO2 and the other set blue for beer gas) and ran them up the wall, through the roof soffit from my cylinders located outside, from there I went across my garage attic, down the wall that my bar is connected to and then snaked it around the inside of my bar and around to my kegerator.  

I had previously made a hidden stowaway compartment at the end cap of my bar using a magnetic panel that I can pop on or off for easy access.  I found a gas line splitter online and used it to connect both of my gas lines to, which then allowed me to turn on or off either stream of gas to easily and quickly be able to switch between a regular or nitro keg.  All in all, I ended up with a slick and sleek final setup, which was the culmination of a lot of hard, quite sweaty attic work.            

Materials & Supplies Based on Gas Cylinder Sizes

Want to create a similar setup?  Below is a short list of supplies I used for this project.  Step up your game even further by visiting The Shop where you can find a variety of other home bar related items I use in my world famous garage Speakeasy.

red gas line air hose, 25 feet

Red Gas Line Air Hose - 25 ft. 5/16 ID, 9/16 OD

blue gas line air hose, 25 feet

Blue Gas Line Air Hose - 25 ft. 5/16 ID, 9/16 OD

Taprite double gauge regulator, brass

Taprite Double Gauge Regulator, Brass

3-Way Shut Off Valve

3-Way Shut Off Valve

More Questions about Keg Logistics & Gas Cylinder Sizes?

Post them on the Bourboneur Facebook Page so you can get your home bar or garage bar up and running like a pro.

You can also order kegerator supplies and accessories directly from The Shop at

Bourboneur Glencairn Glass


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