Guide to Corny Kegging

There is uncertainty in the unknown. Kegging a beer sounds easy but to the beginner kegger it can be a little mind-boggling. So many questions come to mind from what gear is needed to how to operate your chosen set up. Well, as they say Superior preparation rarely tastes defeat, so here is my guide.

A basic set up requires the following:

  • Cornelius keg
  • Gas regulator
  • Gas tank
  • Beer/Gas line and fittings
  • Disconnects
  • Beer Tap
  • No 22 Combination Spanner
  • Adjustable Spanner
  • 19l Of Your Finest Home brewed Beer

The basics

Cornelius keg

Most soft drink kegs will work for the home brewer but they fall into two types: Pin Lock and Ball Lock. The former are used by Coca Cola and the latter by Pepsi. They are both very similar but when deciding which to buy bear in mind that you need different disconnects for each type. The ball lock type seems to be the easiest to come by and can cost from 40 Euro upwards for a reconditioned keg and significantly more for a new one. We will concentrate on the Ball Lock type in this article. The Ball Lock refers to ball bearings that hold the disconnects to the IN and OUT posts. The IN post takes the gas (grey disconnect) and the OUT post is where the beer will exit (black disconnect). These posts usually have different types of nuts and these are not interchangeable. The IN post has a small tube while the OUT post has a long tube that reaches to the bottom of the keg. Each post has a gasket (known as poppets) that is pushed down once the disconnect is placed on top of it allowing a flow. The posts can be removed for cleaning and the gaskets pop out.

The keg also has a pressure release valve on the lid to vent the gas from the keg. The lid also has an O ring that helps to seal the keg.

A – Rubber O ring

B – Lid

C –Safety vent

D – Lid handle

E – In post

F – Poppet

G – Gas tube

A – Out Post

B – Lid

C –Safety vent

D – In Post


These are essential. They connect the keg to the taps and the regulator to the keg. They are for sale from 15 Euro each but you cannot do without them. The Grey disconnect is for the gas and is connected to the IN post on the keg. The Black is for the liquid and is connected to the OUT post on the keg. They snap onto the posts and can be taken off by pulling up the base thus releasing the ball bearings from the collar they sit in (hence the name ball lock). As mentioned at the start there are two different types of kegs. The second type being the the Pin Lock. In comparison Pin Lock disconnects, usually red with black or grey bases, slide down the pins on the posts and are twisted to secure in place. Either way each disconnect will have a threaded fitting or a barbed fitting which is used to connect beer/gas line to the tap or regulator. If the disconnect has a threaded fitting the easier thing to do is fit it with a plastic fitting (usually a John Guest fitting). These are very quick and easy to use as the beer/gas line pushes in and forms a perfect seal (quick and easy if you are in a hurry but they are more expensive). On the other hand if the disconnect has a barbed fitting (built in) the beer/gas line must be pushed over the barbs to be held in place. Heating the line in hot water will help to make it more pliable and easier to fit.You can also purchase a threaded barbed fitting for the disconnect that would screw onto it like the plastic fitting. These are more sturdy. You can see the disconnects in position on the keg in the first picture in this article.

A – Out Disconnect

B – In Disconnect

C – John Guest fittings

D – 3/16 beer line

E – 5/8 beer/gas line


A – The Threaded fitting

B – The Barbed fitting

The disconnects can be taken apart for cleaning using a screwdriver (see below). This is not a big job and should be done after every batch to eliminate yeast build up and nasties. Inside the disconnect is a small rubber washer, a spring and a plastic pin. When in use the pin is pushed down on the in/out post while the disconnect is snapped on. This creates a pathway between tap and keg or gas regulator and gas in post allowing us to feed the keg with gas and draw off our beer.

The disconnect taken apart.

Gas regulator

The regulator acts to safely dispense the gas tank at a pressure that we want. The pressure in a gas tank can be extremely high and safety must be paramount when handling one. The regulator will take the pressure from the tank and, as its name suggests, regulate it to a pressure we can use. One regulator is essential. This will be known as the primary regulator and is connected to the gas tank. This regulator can have two gauges (dual gauge) showing what pressure is being dispensed and the other showing how much gas is left in the tank. It is not essential to have the second gauge. In my experience the latter gauge is not always correct but it’s an indicator of what may be left and gives you a heads up of when to head off to the Co2 store. The dispensing gauge can be changed by turning the dial or screw to get the desired pressure. The regulator connects to the tank via a nut that should be tightened with an adjustable spanner. Try to avoid wing nuts as you cannot be sure of a seal. The smallest leak from the tank could mean in a few months’ time you have no gas left. The other outlet is where the gas line goes. A John Guest fitting will secure the gas line to the regulator. Do not over tighten these plastic connectors as they do crack easily enough. Finally there is a pressure release valve to enable the gauge to vent the tank if necessary.

A – Primary gauge (determines pressure to keg)

B – Secondary gauge (shows what pressure is in the tank)

C – Screw that controls the pressure applied to the keg or manifold

D – Gas out John Guest fitting

E – Nut to attach regulator to gas tank

F- Pressure release

A Secondary regulator showing the different types of threaded connectors that are available (brass and plastic).

Gas Tank

These come in various sizes from a kilo to pub sized gas tanks. Think of what kind of set up you are going to have before deciding what size to go for. It’s hard to lug a pub sized Co2 tank to your mates to watch the match and have a few brews. Most of us will be using Co2 to dispense our beer and these tanks are easy enough to find. They start at about 30 Euro. If nitro stouts are your thing then you will require a mixed gas tank, a nitro tap (a restrictor plate impedes the flow and forces the beer and gas through tiny holes creating that creamy look) and a different regulator as the pressure is typically higher while storing and dispensing. Your gas tank should be kept cool at all times. We don’t have huge weather variations here so it is probably not a big concern but if the liquid gas rises in temperature it will expand and the chance of an explosion does exist. Warning: Gas tanks can be very dangerous if not treated correctly. Always keep them upright when in use and never dial the pressure above the recommended ranges.

Beer and Gas line

There are various widths of line on the market and it will depend on the fittings attached to the disconnects to determine what you need. Using John Guest fittings (JG) or the like in your system will enable you to connect your beer and gas line easily. The gas line is usually 3/8” width and the JG fittings will connect to the regulator via a threaded nut on one end and a push in fitting for the line on the other end. The gas line then is connected to the grey disconnect (IN post) on the keg. The disconnect will have the same JG connector as the regulator. The OUT post or black disconnect on the keg will also have the same JG fitting but if you are using flow control taps you have the choice of using 3/8” or 3/16” beer line. If it is the latter then another JG fitting will convert the line to take the smaller beer line size. So which size beer line do you need? The main considerations are the distance between tap and keg and the pressure in the keg. The closer the tap is to the keg the more pressure needs to be taken out of the beer to avoid foaming. I have used both size lines on my kegerator but only the smaller line when I have a tap attached to the keg top/handle. The more pressure in the keg the longer the beer line needed to avoid foaming. If you are using a smaller line then less will be needed.


The two options are either a flow control tap or a picnic tap depending on how and where you wish to dispense your brew. If you have a fridge then flow control taps would be worth the investment. These can be mounted on the fridge door or a hole can be drilled directly into the corny handle. These taps give you complete control over the flow of your beer. Restricting the flow will decrease foaming. This type of tap will take well carbonated beer better than a picnic tap. Picnic taps are very handy when transporting your keg to a party but unless you have long lengths of beer line the pressure from the keg will cause huge amount of foaming. The only way to avoid this with a short beer line is to vent the keg and use just enough gas to push the beer out of the keg.

A – Picnic Tap and line with disconnect

B – Flow control tap

C – Screw on JG fitting for 3/16” beer line

If your choice is for flow control taps and a fridge the taps can be mounted as such.

So that is the basics of the equipment but how does it all go together, how do you carbonate the beer and how to dispense the liquid gold inside? You have to ask yourself a few questions first.

Do you have space for more than one keg?

Would you have room for a beer fridge?

Are you ready to have beer on tap at arm’s reach every day of the week?

Well one keg is never enough really. We all like to have a few brews on the go so having a few kegs has its benefits. This is easily done using just one Co2 bottle. You can use the cheaper option where you split the gas line to feed each keg (but they will all have the same pressure) or the more expensive option where you buy inline regulators in a manifold or make one yourself using single regulators connected by JG fittings and gas line. Making a manifold is actually easy enough whether you use regulators or just split the gas line using JG fittings. The advantage of using more than one regulator is that you can dial in whatever pressure is needed for a certain carbonation level for that style of beer.

A – Gas line in

B – Regulator

C – Gas line to keg

D – 3/8 line connecting each regulator


Once you have your equipment you need to ensure it is clean and sanitised. The keg can be completely dismantled by taking off the IN and OUT post using the combination spanner. The inner tubes can then be removed. The lid can be separated from the O ring. The poppets can be removed from the posts and all can be soaked in a brewing cleaner to remove all dirt and traces of cola syrup. The hole at the top of the keg is fairly tight and most people would find it difficult to get an arm in the scrub it out so a large carboy brush may be a better option. It is important to ensure all rubber rings are intact and no wear has occurred as this can lead to leaks or dastardly infections. All rubber rings can be replaced and can be bought online. Note: Consideration of what type of cleaner and sanitiser is important as those that contain bleach or ammonia will corrode stainless steel in time. To sanitise the keg use a sanitising solution such as Star San. Assemble the keg and pour in the solution. Close the lid and shake to ensure contact with all surfaces. The posts can be soaked prior to this. Star San foams nicely so when emptying the keg all the foam will not run out. This is an advantage as when the keg is being filled the foam will rise to the top and push out the opening ensuring nothing else can get into the keg whilst filling is on-going. Cleaning your beer line after every brew is good practice and will help avoid contamination and while sanitising the keg is an ideal time to do it. Gas is pumped into the keg via the grey disconnect and the sanitiser will be pushed through the lines and out the tap. To ensure no sanitiser is left in the line, cooled boiled water can be flushed through after. Disconnects can also be taken apart for cleaning. The top can be unscrewed and the internal parts come out. Note: If it is the first time to use a particular keg ensure that it will seal properly by filling the keg with liquid and fill the dead space with gas. The internal pressure will push the lid tighter, ensuring a seal, so do not despair if your keg leaks with no gas in it. When not in use the keg can be pumped with a little gas to keep anything from setting up home. Filling the Keg This is no different from filling a pressure barrel or bottle in principal. Do not over fill the keg as beer may get into the gas line and even into the regulator. When the beer is in and the lid is put in place connect the keg to your gas tank. Add gas and vent a few times to ensure no oxygen is left in the keg as this will cause spoilage. Be careful not to overfill the keg AND dial too much gas into it as when you hook it up to your kegerator set up it may blow beer into the gas line and into the regulator which could ruin the reg for good. To avoid this you must ensure the pressure in the keg is roughly the same or lower then the pressure being applied by the regulator.


Firstly we must understand what carbonation is and how it is measured. Carbonation is measured in Volumes of CO2. One volume of CO2 is equal to one litre of carbon dioxide dissolved in one litre of liquid, two volumes is equal to two litres of gas in one litre of liquid and so forth. The higher the volume of CO2 in the liquid the more fizziness we perceive to be there. An example of this would be the levels in British cask ales and American Lagers. The British ales will have a low volume of CO2 compared to the American lagers. The cask ale could have a volume of 1.5-1.8 while the lagers might have between 2.5-2.9 volumes. For a more detailed list of CO2 volumes see the table below or try this very handy calculator on BrewBlogger.

So how does this affect us when kegging? Well, once again we have options. You can prime as you would do with a plastic kegs/bottles or you can force carbonate but either way you must have in mind the CO2 volume that you want or that is suitable to the style. To carbonate I like to use the latter option. Within this option are yet more options. These are commonly known as the set and wait method and the shake method. The set and wait method is the easiest and is for people with a bit more time on their hands. All you do is dial in the pressure required and walk away. In a week your beer will be carbonated. The shake method involves pressurising the keg and shaking it until the gas is absorbed into solution. This can be done by rolling the keg whilst gas is being forced into it. When a larger surface area of the liquid is exposed to the gas the result is that the gas will be absorbed quicker into the liquid. This is repeated until the gas stops hissing, meaning no more gas can be pushed into solution. Although this is quicker it requires time to settle to avoid foaming. Care must be taken to ensure your gas tank is secured while rolling or shaking and to avoid beer going into the gas line and to the regulator. All carbonation is dependent on gas pressure and beer temperature. The beer temperature is of huge importance. The cooler the beer is the more CO2 will be absorbed by it. If the beer is very cold and a high pressure is dialled in you could end up with an undrinkable beer. The only way to rid the beer of this excess gas is to bring it to a higher temp and bleed off the excess gas through the vent over a few days as the gas will leave solution in higher temperatures. I would be an advocate of the set and wait method. I am in no hurry to drink the beer as I want it to mature and cold condition. I would dial in 10 or 12psi and leave it for a week or two at a temperature of 7c. I would leave the gas on until I was happy with it. I would turn the gas off if I thought I would not be drinking for a few days in case of any leaks. This is not necessary but I hate to lose a bottle of gas. To keep your beer in good condition and to ensure carbonation levels, my advice (in an ideal world) would be to get a dedicated fridge. Cold conditioning your beer will clear it if that’s your bag and a couple of months in a fridge would clear anything. Having the fridge allows the beer to be served at the same temperature so carbonation will always occur at a rate you can get your head around. Every system is different and you will get used to your set up very quickly but it may take a bit of playing around with line lengths and beer pressure.

Degrees C PSI
5 10 15 20
2 2.0 2.5 3.0 3.6
3 1.9 2.38 2.9 3.4
4 1.8 2.3 2.7 3.2
7 1.7 2.1 2.5 2.9
10 1.5 1.9 2.3 2.7
13 1.4 1.8 2.1 2.1


Once the beer is cold and carbonated we will want to pour it. This is a science in itself in that there are mathematical equations to calculate beer line length that take into account the height of the tap from the centre of the keg and the restriction caused by the line on the flow. Again, if you don’t fancy getting out the pen and paper a little bit of trial and error will do it. The smaller the beer line the more resistance there is which means the beer will have less pressure coming out of the tap. Basically the slower the beer comes out the more gas stays in solution, causing the beer to foaming less. For more detailed information on a balanced system see Micromatic. Too much foaming can be an issue but with a flow control tap you can manage this to some extent but the beer will take a while to pour. I find a couple of feet of beer line is more than enough and it gives a decent flow and foam but the pressure in the keg and the length of beer line are the factors that need to be taken into account to fix this problem. It can be an expensive hobby at times and this element could be considered nonessential and expensive. But once you get your kegs there is no way you would go back to bottling. It takes very little time to keg and a good clean every now and again of the keg along with the usual sanitisation needed for good beer will at least cut in half those bottling day traumas. So instead of hording all those bottles and trying to nick the swing tops from the B&C get into kegging. Get out to the beer fridge and pour yourself a scoop, sit back, relax and have a homebrew.


Here are a few links to where you can purchase kegging related items.

Irish Sites

The HomeBrew Company

My Beer and Wine

HomeBrew West

U.K based shops

The Hop Shop

Hop and Grape

Norm’s ebay shop

Advanced Reading

Balancing a system

Force Carbonation Chart

How to connect your Corny Keg

Hover over for more details

Author: Bubbles, pob

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