Kegging your beer is a goal to which every homebrewer should aspire. Pouring your very own beer from a keg is something that all homebrewers should experience at some point in their brewing. My own personal kegging journey led me to build the now nearly-famous
. But before the GFP, I started like everyone else, wondering what kegging was all about, how it worked, all the equipment I needed, and how much it would cost me. Read on… Great Fridge Project
The first thing you need to know is that kegging is totally worth it. Yes, you will spend money. Yes, it requires some dedicated equipment. Yes, you will need to dedicate a refrigerator to the cause. But even after all that, it’s totally worth it. The convenience, the virtual elimination of the bottling process (bottling from a keg is possible,
look here), the decreased time line from brew day to brew sampling (by about 3 weeks), and the precise control over carbonation levels all add up to a huge advantage of kegging over bottling. The next thing you need to realize is that any shortcuts you take in your kegging set-up are going to result in a less than optimal kegging experience.
The first item on the list is obviously the keg itself. For homebrewing, you will be using a 5 gallon soda keg, formerly used in the soft drink industry. This size and type of keg is perfect for the homebrewer and pretty much the universal choice for homebrewing in general. There are several different manufacturers of these types of kegs and they differ ever so slightly in their design, but they all operate pretty much the same. There is an oval lid in the top that seals via a large O-ring in a clever design that uses internal pressure to help seal the keg as shown below:
Soda Keg Lid Design
The lid also has a pressure relief valve on it that prevents over-pressurizing the keg and also allows the user to bleed off pressure if necessary. The valve design varies a bit, but they all do the same thing. I have seen a few kegs over the years that did not have a pressure relief valve. These tend to be older kegs and are fairly rare. If presented with a keg for purchase that does not have a pressure relief valve, I would pass. If they are giving it away, go for it.
Relief Valve Designs in Keg Lid
There are two connections (posts) on the keg – one for CO2 into the keg to apply pressure and push the beer out, and one for liquid from which beer flows out of the keg. On most kegs, these are labeled on the keg exterior by molding the words “IN” and “OUT” into the rubber handle or stamped on the keg itself. The connections are “poppet” type connections where internal pressure keeps the valve closed and the top of the “poppet” needs to be depressed in order for the valve to open. Both the CO2 and liquid poppet connections are identical in their operation, but there are safeguards in place to make sure that two do not get confused.
The gas line is meant to pressurize the keg from the top downward. For this reason, there is a very short tube on this connection that is meant to always be above any liquid that is in the keg.
Gas In Connection Post on Keg
Gas-In Tube Extending into Keg Interior (back view from photo above)
The liquid line is meant to draw beer out of the keg from the bottom up. For this reason, there is a long dip tube that extends downward into the keg to the very bottom to make sure that it is always below the liquid line.
Liquid Outlet Fitting
Outlet Dip Tube (view opposite side from photo above)
It is extremely important not to get these lines confused. You do not want to accidentally attach the gas line to the liquid connection and potentially force beer into your gas line. To help prevent this, the kegs have been designed with connectors that are not interchangeable – meaning that you physically cannot mix them up. However, there are some limitations to this. The connector design and the geometry of the keg is what differentiates the two types of kegs available to the homebrewer as shown below.
Ball Lock vs. Pin Lock
Keg Types: Ball Lock (left), Pin Lock (right)
End View of Kegs: Ball Lock (left), Pin Lock (right)
As you can see, the geometry of the two kegs is the most significant difference between the two. Below is a description of both types.
1. Ball Lock
The ball lock keg is about 24-1/2″ tall and about 8-1/2″ in diameter and is the more common type found in homebrewing. It is the taller and narrower of the two types. These are former kegs used by Pepsi and the Pepsi family of products. The “ball-lock” moniker refers to the mechanism by which the connectors for the keg attach. Namely, a ring of ball bearings that engage a groove on the keg connector post as shown below.
Ball Lock Connector Design
The design of the keg connector post is such that the liquid side has a slightly larger ridge diameter than the gas line. That means it is “almost” impossible to accidentally put the gas connector on the liquid side. I say “almost” because it is actually possible to do if you push hard enough. I speak as the voice of experience on this. Believe me, once you actually pull this feat off, it is far harder to remove the connector than it was to push it on.
In addition to the “IN” and “OUT” labels on the keg, the “IN” keg post has a visible notch around the wrench flats to make it stand out as the gas line.
2. Pin Lock
The pin lock keg is about 22″ tall and about 9″ in diameter. It is the shorter and fatter of the two types and is less common – but still readily available. These are former kegs used by Coco-Cola and the like. As you can imagine, the “pin-lock” moniker refers to the engagement pins to which the keg connector engages. See below.
Pin Lock Connector Design
The design on the keg connector post between the liquid and gas is a little more obvious than the ball lock in that the “IN” keg post for the gas has only two connector pins 180° apart while the “OUT” post for the liquid has 3 connector pins 120° apart. This makes it nearly impossible to mix up the two connectors
There are minor differences in kegs based on the manufacturer but these are mostly cosmetic such as the handle design or the locking mechanism for the lid. This can vary by manufacturer. The major manufacturers of these soda kegs are:
It doesn’t really matter which manufacturer you choose, the ball lock or pin lock from each one will be the same overall dimensions and have the same interface to the external connectors. The only difference will be any internal parts such as the poppets or relief valves.
Because the pin locks are slightly larger in diameter than the ball locks, your choice of keg designs may depend on the storage space that you have for them. For an upright refrigerator where horizontal space is very critical, the pin locks are probably a better choice since they will take up less room horizontally. For horizontal storage like a temperature controlled chest freezer, where the vertical space is more critical, the pin locks are a better choice.
New vs. Used
You will likely get your keg used – although new kegs are available. New kegs are going to cost you at least $100 each, but if you are patient and look hard enough, you can find used kegs for less than $30 each. If you buy used (which I do recommend), you will want to make sure that the keg will hold pressure and does not leak. If you buy from an online retailer (many sell used kegs regularly), this will not be a problem, but if you buy from some stranger on Craigslist, you better be sure. Also, since you are buying used, the cheaper the keg, the more likely it has not been cleaned. This can be anything from slightly inconvenient to absolutely disgusting depending on what the keg’s last duty was and how long it has sat. The good news is that the kegs are stainless steel and a good long soak in PBW (Powdered Brewery Wash, a highly recommended alkaline cleaner) and some elbow grease will usually clean them right up. Also, I would strongly suggest replacing all of the O-rings. Check the poppets carefully and if there are any doubts about sealing, replace the poppets as well.
Poppet Valve and O-ring on Keg Post
Since the keg is going to be a substantial part of your kegging set-up, don’t skimp. Spending a little extra money to get a nice keg that isn’t beat up and has all new seals on it is definitely worthwhile. It also helps if all your kegs are identical (same type and manufacturer) so that if you have to clean multiple kegs at a time, you know for sure that all of the parts are interchangeable.
The keg connectors are the fittings that interface between the CO2 and the beer line. You will need to match the connector to the type of keg you have – ball lock or pin lock.
Ball Lock Connector (left), Pin Lock Connector (right)
There are slight differences in various brands, but they are all about the same. The only thing you really need to decide on is how your connectors interface with your gas and liquid lines – namely, a barb connection or a removable type connection (flare connection).
Barb Interface (left), Flare Interface (right)
I’ll be honest and state that the vast majority of homebrewers pick the barb connection. It is certainly the easiest and most straightforward of the two. It also offers the least amount of functionality. I touch on this in my article on
Plumbing for . I have a personal aversion to barbs as the main connection for virtually anything. Basically, once you attach tubing to it – that’s it. If you ever want to remove the tubing, you have to cut it off which is less than optimal since cleaning the fitting and periodically replacing tubing is pretty much mandatory. On the other hand, the flare type allows easy removal and replacement which gives maximum flexibility for the brewer. Read the referenced article for a detailed discussion. The size and thread type for these connectors is 1/4″ Male Flare. the HERMIT brewery
You need to push the beer out of the keg using CO2. This is a part of the system that you really shouldn’t skimp on. You need to get a CO2 tank and regulator for this which is also a major part of the expense involved in kegging. This is also a point to make a decision about the size of the CO2 tank that you buy. They typically come as small as 5 lbs (although I have seen 2.5 lb models) up to 20 lbs – and I have even seen them as large as 35 lbs. A smaller tank is more portable but will need to be filled more often while the 20 lb tank will last for quite a while, but is heavy to lug around. Keep in mind that you will likely opt for force carbonation for your beer. That means you will be using the CO2 in your tank to carbonate 5 gallons of beer as well as push it all out of the keg. For a typical carbonation level, carbonating and pushing out 5 gallons will use about 0.33 lbs of CO2. That does not include any waste or accidental venting of CO2 along the way. I think 15% is a good number for this, so, a small 5 lb tank will serve you for about 13, 5 gallon kegs, and the 20 lb tank will get you about 52 or so. Depending on how often you brew, the smaller tank might be fine, but just remember, things like leaks and accidental ventings can add up quickly and use up your CO2 far faster than you thought. My recommendation is to get as big a tank as you can manage.
You will need a CO2 regulator for you tank. The regulator will fit any standard sized tank from 5 lbs on up. The regulator is necessary because the pressure inside the tank is going to be around 800 PSI at room temperature. There is actually liquid CO2 inside the vessel that will exert this amount of pressure as long as there is liquid present. The regulator allows you to dial in a specific pressure more suited to beer and control that pressure constantly.
The regulator shown above is a 2 gage regulator, meaning that one of the gages reads the actual tank pressure (around 800 PSI at room temp) called the high-pressure gage, and the other reads the regulated pressure, called the low-pressure gage. The regulated pressure can be adjusted by turning the screw in the center of the device. There are 1 gage regulators that you can purchase that are a few bucks less and only have the gage for the regulated pressure. I don’t recommend these. Your tank will sit at 800 PSI for 99% of it’s life and it seems silly to have something there that never changes – but once the liquid CO2 inside the cylinder is gone, this pressure inside the tank will start to drop from 800 PSI and that means that you will need to fill your tank pretty soon. The high pressure gage tells you this very quickly as you can see the pressure dip below the 800 mark. If you only have the low pressure gage to go by, you will be getting ready for a party with multiple kegs of homebrew and wonder why you can’t crank the pressure up past 8 PSI. Think of the high-pressure gage as insurance.
Standard 2-Gage Regulator
When you buy your regulator, make sure you get one with a shut-off valve (shown at the lower end of the regulator in the photo above). This will allow you to quickly turn off the CO2 source to your kegs.
The line you use to get CO2 from the tank into the keg is not really that critical. It can be virtually any size, but it should be flexible and provide an adequate pressure rating. If you purchase your regulator with a standard shut-off valve with a barb connection, this is going to be 1/4″ ID tubing. You have some options on gas distribution for multiple kegs that falls out of the scope of this article. I would recommend reading
which is a chronicle of my own fridge conversion where I take a very different look at how to run the CO2 lines. The Great Fridge Project
Lastly on CO2, there is always the question of “What if I want to take my keg somewhere and don’t want to haul my CO2 tank?”. Good question. You have a couple of options. The first and most expensive option is to buy a second smaller tank. Someone in my homebrew club was divesting himself of all his brewing equipment and had a 5 lb tank he was practically giving away. I snatched it up and it has become my portable tank for off-site events, brewing chores, etc. The other option is a slick little device that uses the small 12 gram CO2 cartridges for air rifles.
Portable CO2 Injector
The device uses a screw on connection to your keg connector, so you will need a connector with the 1/4″ Male Flare described previously. The device uses a trigger and you simply add CO2 whenever your keg needs it. This is solely for beer that is already carbonated in a pressurized keg. I own one of these and it has come in very handy and fits in your pocket – but it is no substitute for a real CO2 tank.
A dedicated fridge for your kegs is pretty much mandatory for kegging. You need to keep your beer cold and let’s face it, trying to make room in the kitchen fridge for a couple of kegs is going to be a very tall order. You don’t have to spend a lot of money – in fact, this is a great place to skimp and find a bargain. I got my first kegging fridge from the classifieds for $25. It doesn’t have to be pretty, it just has to work and have room for what you want to put in it. There are no hard and fast rules on the style of fridge you choose, only that it meet your needs. There is an option to use a horizontal type chest freezer if desired, however, you will need to attach an extra device so that the freezer will keep your beer at refrigerator temps. This device is an external temperature controller that can be picked up at most homebrew retailers and controls the power to the refrigerator using a separate probe to measure the interior temperature and then cycles the power on and off accordingly. I have never used these but the word from those that have is that they work great.
If you read
you will see that I went to some lengths to customize my fridge to my own whims and desires. However, the GFP was foremost The Great Fridge Project, functional and secondarily cosmetic. I would recommend the same approach. Your fridge has to operate conveniently and consistently to truly be a benefit to you. If it’s a little ugly, that can be tolerated far more than one that doesn’t hold temp, or worse, freezes your beer. When the time comes, you can always trick out the fridge with faucets and a fancy gas manifold. Speaking of which…
Faucets & Shanks
Dispensing your beer is the most important thing about kegging. You need to be able to pour a proper pint consistently to truly reap the benefits of kegging. Do you have to have fancy beer faucets on the outside of the fridge to do this? The answer is a resounding – NO. This is another place where you can take a couple of shortcuts. The absolute cheapest option for faucets is the lowly cobra tap.
Cobra Tap or Picnic Faucet
This is also called the “picnic faucet” and is used at nearly every frat party across the country. It’s cheap, simple, and reliable. In order to get the best performance from it, you have to understand how pouring beer works. I will discuss this in detail under
but for now, just realize that using the cobra tap is perfectly fine as long as you set everything up right. Beer Line
However, if you want to upgrade, nothing says draft beer like a genuine beer faucet.
The beer faucet establishes a sort of authenticity to your kegging system. It says, “I have arrived”. There are several different models of faucets, each with their own pros and cons. The first is your basic standard bar faucet:
Standard Beer Faucet
These are used in most bars and restaurants and are the faucets that I purchased when I set up my first keg fridge. They are the least expensive beer faucet at about $15 each. While these work fine in a production environment like a bar, they don’t work so well on a home system. Due to their design, they seal in the rear of the faucet and expose most of the faucet body to the air when the faucet is closed. In a bar, beer is poured often and these faucets are cleaned daily. At home, this is not the case. You might go a few days between pours at home and this is a real problem. As the faucet body sits, exposed to air with sticky beer residue in it, even after only a day, it will crust up and cause the faucet handle to stick – making it very hard to open. The longer it sits, the harder it sticks. I remember once after about a week of inactivity, the handle was stuck solid. I had to remove the faucet from the fridge completely and clean it thoroughly to fix it. And it’s not just the sticking. Air and beer make mold. Lots of it. These faucets grow mold very fast and need to be cleaned often. Suffice it to say, for a home system, steer clear of these faucets.
The real improvement in faucet design came with the introduction of the “forward sealing” faucet pioneered by Perlick. These faucets seal in the front of the faucet body keeping liquid in the faucet at all times. Sticking is virtually eliminated and I can say from experience that they can go weeks between cleanings.
Forward Sealing Faucet
I cannot recommend these faucets highly enough. Yes, they do cost a little more, but trust me, you will be much happier with them over the standard faucet.
In addition to the faucet, you will need a shank. This is the large bulkhead that passes through the wall of the fridge where the beer line from the keg is connected on the inside of the fridge, and the faucet is attached on the outside of the fridge. The shank is held in place with a large nut that will come with it. The line from the keg is attached to a nipple (basically a barb) on the end of the shank. This nipple can be supplied as an integral part of the shank (sometimes called a nipple shank) or as an add-on piece (called a tail piece). The opposite end of the shank has a special connection where the beer faucet is screwed on.
Nipple Shank (above), Shank with Tail Piece (below)
The shank can be purchased in virtually any length depending on the application. For a typical fridge, it will be something in the 3-1/2 to 4 inch range. You will need to measure your fridge door thickness to determine how long a shank you will need. Remember that if you buy a shank a little longer than you need it, it won’t hurt a thing, it will just protrude into the interior space a little more. If you are unsure, you might want to buy one a little longer than you think you need.
Beer Faucet Assembly
In order to achieve a leak free connection with the faucet, you will need a faucet wrench to attach and detach the faucet.
As with anything else, faucets and shanks come in various price ranges. If you want the Cadillac, you can get all stainless steel. If you are on a budget, chrome plated brass is usually fine. Shop around, there are lots of places to source your faucets and shanks and get the best deal. Don’t be afraid to buy used on these either. Used faucets and shanks are perfectly fine.
The liquid line to carry the beer from keg to faucet is extremely important.
This is where many homebrewers go wrong and pay the price. This is not a place to skimp in your kegging system. The good news is, quality beer line is a minor expense compared to everything else, but it will disappoint you greatly if you try to cut corners.
First, get real beer line. Buy from a place that sells tubing specifically for beer/beverages. Next, buy tubing that measures 3/16″ ID and 7/16″ OD – period. If you get anything from this lengthy article, let this be it. The ID is extremely important because it provides the flow resistance that will allow you to pour beer at 12 PSI from the keg and dispense it into a glass without shooting foam everywhere. This size line provides a flow restriction of about 2.2 PSI per foot. That means beer at 12 PSI needs about 5.5 – 6 feet of line to pour correctly. Beer line that is larger than 3/16″ ID has far less resistance. For instance, 1/4″ ID beer line has only 0.80 PSI per foot of resistance. That means you need about 3 times the length for the same pour. Lines this large are for bars where the beer has to travel quite a long way from keg to faucet. Don’t use it. Trust me. Also, the 7/16″ OD on this tubing assures a nice thick wall that is resistant to kinking. The smaller OD tubing (5/16″ OD) doesn’t take a hose clamp very well (it’s just too darn small). So, 3/16″ ID x 7/16″ OD. Got it? Nothing else. Trust me.
When calculating the length of tubing that you need for your kegging system, you have to take into account the pressure at which you will be serving (i.e. the carbonation level of your beer). This is discussed in detail below. Once you determine your overall serving pressure, take that pressure and divide it by 2.2 (the pressure drop per foot of 3/16″ ID beer line). This will give you the length of beer line, in feet, that you will need. For example, I typically serve all my beers at 12 PSI:
12 PSI ÷ 2.2 PSI/ft = 5.45 ft
This means I will need about 5.5 feet of 3/16″ beer line for each line on my kegging system. The other thing that you need to take into account is the faucets you will be using. Beer faucets provide additional resistance to beer flow that make the above calculation come out correctly. However, if you use a cobra tap, this does not provide as much resistance and the beer will tend to flow out faster and foam more than if you are using a beer faucet. For this reason, add an extra foot of tubing if you plan to use the cobra tap.
In general, when buying beer line for your kegging system, buy extra and put in about a foot more line than you think you will need. You can always shorten but adding length is, well, unlikely. It won’t cost much and will save you the headache of having a tube end up too short.
That about covers the equipment for your excursion into kegging. But you aren’t finished yet, there are some process issues that you need to understand before you dive in. The most important of which is…
When we brewed extract beers, we didn’t worry too much about carbonation, as long as we had some in the finished beer and the bottle didn’t blow up, we were happy
. With a kegging system, you can precisely control how much carbonation your beer has and actually change it mid-way through a keg if you want. The way we quantify the carbonation of a particular beer is a term called “volumes of CO2″ or just “volumes”. This is simply a number that represents the volume of CO2 that exists in an equal volume of beer. Beer carbonated to a CO2 volume of 2.3 means that there is 1 liter of CO2 at standard gas conditions for every liter of beer. The volume units don’t actually matter, it can be liters per liter, cubic foot per cubic foot, acre-feet per acre-feet, whatever – it’s all the same. The important thing is that the higher the number, the more carbonation the beer has. To calibrate you a bit, below is a list of various CO2 volumes of different beer styles:
British Style Ales: 1.5 – 2.0
American Ales/Lagers: 2.2 – 2.7
European Lagers: 2.2 – 2.7
Porter/Stout: 1.7 – 2.3
Belgian Ales: 1.9 – 2.4
Lambic: 2.4 – 2.8
Fruit Lambic: 3.0 – 4.5
German Wheat: 3.3 – 4.5
Note that these carbonation levels are the
result of keeping beer at a specific temperature and pressure. The relationship between the two is: the higher the pressure, the higher the carbonation and the lower the temperature, the higher the carbonation. So, low temps and high pressure is the recipe for high carbonation, and high temps and low pressure is the recipe for low carbonation.
Beer at a specific temperature and pressure will have a singular CO2 volume associated with it. If you change the temperature or pressure and let everything come to equilibrium, the beer will reach a different CO2 volume. The table below calculates the resulting CO2 volumes at a given temperature and pressure.
Fill in the yellow boxes in the table above and the resulting CO2 volumes will be calculated in the blue box. Make sure to stay within the ranges specified to the right. Do not enter any values into the blue box. If you accidentally input a number into the blue box, refresh the page and try again.
Note that a keg at 40 °F and 12 PSI has about the same CO2 volumes as a keg at 67 °F and 30 PSI. That would equate to taking a cold keg out of the fridge and allowing it to come to room temperature and not vent any of the CO2 out. As expected, the pressure in the keg is going to rise significantly. But since we don’t drink beer at 67 °F and serving at 30 PSI is a bit cumbersome, we’ll stick to refrigerator temps and the corresponding pressures to give us the carbonation level we want for the beer we are serving.
It is very important to remember that carbonation takes time. It is an
equilibrium process – meaning you have to wait for things to settle out before you will see how things end up. The bigger change you make, the longer you have to wait. Now, there are ways to speed things up and I’ll get to those in a minute, but for now, just realize that if you put a keg in the fridge at 40 F and maintain 12 PSI on it, eventually, you will have a beer with 2.47 CO2 volumes in it. If the beer was completely flat and warm when it went in, this process could take more than a week. If the beer was already carbonated at 10 PSI and 40 F, then it might only take overnight. But regardless, the chart tells you what the equilibrium value will be.
Now, how do we go about the process of getting the CO2 into the beer? I’ve already mentioned one: you fill your keg, put it in the fridge, set your regulator…and wait. This process takes a long time. The CO2 slowly diffuses itself into the beer and eventually you will get where you want to be. This is a week to 10 day process.
There are also devices you can buy to speed up the diffusion process. One is called a “carbonation lid” where you buy a special lid for your keg with a gas connector fitting mounted in it. On the under side is a long tube with a fine mesh diffuser on the end that is submerged in the beer when you install the lid:
Using one of these will condense the process down to about a day and a half which is significantly quicker. You will also drop about $60 on one of these. Ouch.
For the 12+ years that I have been kegging, I have used a different method that gets me carbonated beer in about 24 hours. It takes some practice and some personal calibration on your part, but it is fairly easy and requires no additional equipment. This is what I call the “Shake Method”. The name implies exactly what it is. Below is a short synopsis of this method:
There are some variables in this method and they will change from brewer to brewer such as:
There is always the risk of over-carbonating your beer using this method, but the trick is to err on the low side and increase pressure or shaking time to dial in the right amount as you gain experience. As I said, you will have to calibrate yourself to this method and alter the variables accordingly. Know that reducing shaking time will yield the same result as lowering the pressure and shaking for the same amount of time. Don’t alter too many variables at once or you will chase your tail. The values I state above are a good starting point.
Kegging is not for the faint of heart. It requires some serious commitment and a specialized list of equipment – but the pay-off cannot be matched. Pouring your beer from your own kegging system
is a true brewers dream. Just remember: