Kegging 101

Beer bottles are classic in keeping and serving beer. They contain your beverage at its carbonation and are easy to carry around and share with people. But, they are also annoying to package in as a homebrewer, and can be monetarily costly if buying new or time consuming if cleaning old, plus the time spent getting all your beer into those bottles. If they didn’t start out with a kegging system, homebrewers often start thinking about kegging as soon as they have cleaned bottles for their first batch. But what’s involved and when is it time to make the jump?

Pros and Cons

Beer on draught is always more appealing. There’s something about pouring your own beer from a tap that a bottle or can will never be able to compete with. In addition to being able to pour yourself a beer from the comfort of your own home, kegging means no more need for bottle conditioning (or waiting weeks for bottles to carbonate) and of course, no more bottles to clean. It’s hard to see any downsides to that, specifically the no more bottles part, but like anything that seems too good to be true, it
usually is. 

For simplicity we will focus on Cornelius kegs (commonly called Corny kegs) in this article as they are what most homebrewers use, vs. the Sankey kegs commercial breweries usually use. 

To preface, any downsides to switching to kegs are reasonably overcome with some tweaking here and there, but one of the biggest cons is cost. Kegs, CO₂ canisters, regulators, and kegerators are all pricey. Depending on how you want to serve your kegged beer, you can go down the cost effective route with a picnic tap, or with a bigger budget go with the full draught setup. 

One of the other downsides is space. With bottles it’s a brewer’s preference in regards to storing in a fridge or not (once carbonated, I always recommend it, though!) while kegs need to be kept cool at all times. With that in mind, you will at least need a small fridge dedicated to your keg(s) or a lot of space in a current fridge that will be used to store your beer. In my case I started out with a small kegerator from a big box store and then decided to build my own keezer once I had the space for it, which now allows me the ability to keep multiple beers on draught. 

One neutral thought is that of draught maintenance, which I don’t necessarily consider a negative except in extra time and effort. Draught lines should be cleaned, maintained, and checked for leaks regularly to ensure proper pouring, carbonation, cleanliness, and no waste is happening. These are at most every once in a while or on an as-needed basis, but line cleaning should be done every two weeks. Another neutral is carbonation, as it can be easier but we’ll discuss that later.

For positives, most standard-sized fridges will allow for one to four 5-gallon (19-L) Corny kegs to fit inside, and if you don’t want to go too fancy, the plastic picnic taps (sometimes called cobra taps) serve beer just the same. Corny kegs are also available in 1-gallon (3.8-L), 3-gallon (11.5-L), and other sizes as well, which could help maximize space efficiency in a kegerator. In many cases, kegerator-specific fridges can hold two Corny kegs tightly as most kegs on the market are roughly the same width, although height and features may change. Bringing a keg to a party is always a fun way to share your beer, and allows everyone to have as much or as little as they want without wasting any bottles. You also have the option to fill a growler, which is often a convenient size to bring to a gathering. Cleaning is usually easier and faster with kegging as you have just one unit to clean (and some pieces) compared to two cases worth of bottles per 5-gallon (19-L) batch. Kegs also allow you to do counter-pressure bottle filling on demand if you would like, which is great for occasions where you want to just bring a couple bottles with you, or for entering competitions.

Familiarize Yourself with Kegs

Before starting, here are some quick facts and history to get you familiar with kegs. Corny kegs are what soda companies used to use to send out the syrup for soda machines to stores and restaurants before switching to the bag-in-a-box, which is the standard today. They got their name from the Cornelius Company, which was one of the main manufacturers of these vessels, and the name stuck, even though there are other manufacturers out there. Today there are a lot of smaller companies who still make new ones, and many homebrewers may have mixed and matched kegs from brand new to ones made in the 70s and bought used. It is worth noting who made your Corny kegs when getting parts as not all parts will fit different brand kegs the same. For example, it took several unresearched buys for a lid gasket to one of my kegs until I found out it was colloquially called a “racetrack” Corny keg, which has a square gasket instead of a round one. Before buying, find out who made the keg so you can find out who has spare parts (the manufacturer’s name is typically etched on the side of the keg). 

Five-gallon (19-L) kegs are by far the most common size, but other sizes can easily be found on the market, ranging from under 2 gallons (8 L) to 10 gallons (38 L) and above. The quick disconnects used for each keg depends on what style of keg you have. They come in two different styles, ball-lock and pin-lock. The main difference is the type of connection posts at the top of the keg. These connection posts are used to connect the gas and the beer line to the keg. Because these kegs were originally made to hold soda syrup, the soda companies did not want their customers to be able to switch between the two brands so they made the connections incompatible with each other. As soda companies no longer use these vessels the supply fluctuates on the used market, although there are many small companies who are making new ones readily available. Because homebrewers tend to prefer the ball-lock style — which was used by Pepsi and soda companies other than Coke — hey tend to be more in demand and therefore the price is often slightly higher.

Made from stainless steel, Corny kegs are pretty simple by design. You have two posts for gas and liquid fittings, a dip tube that goes to the bottom of the keg, and an oval lid that should be fitted with a pressure relief valve. There’s a large O-ring that goes around the lid base, with clamping legs that push onto the top of the keg to lift the lid into sealing position. When looking at used kegs, be sure the lid and clamping leg area are not dented as this will create difficulty with sealing. Buy used kegs from a reputable dealer or ask the individual selling the keg to pressurize it to prove its seal.

The posts for connecting your ball-lock or pin-lock fittings will usually be marked “in” for gas and “out” for beer. The fittings are usually grey in color and in the case of pin-lock have two pins for gas, while the beer side is usually black, with three pins for pin-lock style. A simple trick to remember is “Grey for Gas, Black for Beer.” In most cases, the gas-post will have a line on the nut to tell it apart from the beer-post. 

Fitting Your System to Your Needs

Ideally, you want to decide first if you go with ball-lock or with pin-lock, as that will determine what you do in the future for fittings. Although you can do both, it definitely becomes inconvenient and costly playing the mix and match game on fittings (however, there are quite a few conversion kits on the market now). There are some universal connectors on the market as well but ensure they are made of materials that can handle caustic-based chemicals before purchasing them.

There are a few options you have in regards to size and regulator when purchasing a CO₂ tank. I use a 5-lb. (2.25-kg) tank with a dual regulator. The high pressure gauge measures the gas pressure in the gas tank, while the other gauge measures the outgoing PSI level. Although it lasts me quite a while, it is very top heavy, which has led to a couple accidents in the past. A 10-lb. (4.5-kg) tank or more will decrease the likelihood of your tank falling over, but there’s no reason to go overboard. For a 5-lb. (2.25 kg) tank, I average about 5-7 kegs with carbonating and serving from beginning to end, along with at least one transfer per beer. Just because it’s bigger doesn’t mean it’s better. Tanks from 5–20 lbs. (2.25–9 kg) will more than suffice for most homebrewers. Most welding suppliers will exchange (not fill), your CO₂ tanks when empty — something to consider before spending the extra money on a shiny new one.  

Regulators come with a couple options including single-gauge and dual-gauge. Single-gauge regulators will show the pressure for the gas output (inside the keg), whereas a dual-gauge regulator also includes the pressure in the CO₂ tank. The pressure inside the keg is what we are most concerned with and is very low compared with the pressure in the tank. The high pressure gauge holds steady at around 800 PSI (at room temperature) as long as there is gas in the tank. Once this gauge starts dropping, you are out of gas, as the drop tends to happen pretty quickly. You should not use any type of thread tape on this connection and use the washer provided to ensure a proper seal. Most regulators today come with a ball valve for attaching the hose that will run to the gas-side of your keg.

The next step is deciding what you would like to do with your CO₂ lines.
I would recommend in all cases having a check valve on your gas line to prevent any accidental backflow of beer to shoot into your gas line and cause a mess of cleaning! If you’re only using one keg, maybe the simplistic route is the way to go — a line directly from your regulator to your gas fitting on your keg. If you are setting up multiple kegs you should install a gas manifold that has one main line feeding multiple outputs. If this is the route you want to go, be sure to put a check valve on each line going to a keg, and it is recommended to get secondary regulators for each line, as different beers are best at different levels of carbonation. For tubing, homebrew stores and online retailers generally sell gas- and beer-specific tubing ranging from 3⁄16–3⁄8 inch.  

Something else to consider, which has made my life so much easier, is adding gas quick disconnects. As the CO₂ lines are not in direct contact with beer, brass fittings are fine. These quick disconnects allow you to do many things around your homebrewery such as have small setups for keg transfers, vessel purging, and CO₂ bursts for dry hopping. Make sure you always have your keg CO₂ manifold on a “closed system,” or in other words, the female quick disconnect on your kegerator side so the lines will keep the positive pressure even when disconnected. Always spray each connector with sanitizer or isopropyl alcohol before reconnecting!

In terms of serving, the most cost-effective route is the picnic tap, usually made from black plastic with a small lever on the top. They are easy to use, take apart and clean, and should anything happen to it, cheap to replace. Like all draught systems, it does work best fully open rather than “cracked.” If you want a step up from that but don’t want to drill any holes in your fridge, there are a few conversion kits out there that allow you to put a faucet directly on your beer-out connector for either a ball-lock or pin-lock. The most common way to serve from a keg, however, is installing a faucet either on the tower of your kegerator, coming out of the outer wall of a fridge, or out of the collar of a chest freezer (keezer).

All of this only applies to CO₂-only systems. If you would like to include a nitrogen tap for beers such as dry stouts, this will require extra equipment and a different gas mixture called “beer gas,” which is a mixture of nitrogen and CO₂. This uses a different cylinder and requires a different regulator for that specific cylinder. In most cases for this you would use a specialty faucet as well that is designed for nitro beers. (To set up a nitrogen kegging system, digital members can refer to the article “Nitrogen Draft Systems” at: https://byo.com/article/nitrogen-draft-systems/

Cleaning Your Kegs

When first purchasing your kegs you want to make sure they are thoroughly cleaned. Used kegs in many cases are pressure tested and that’s about it. Before opening a used keg, always depressurize it with the relief valve and don’t be surprised to find remains of what they previously held in them. In many cases, before even starting, you may want to replace all of the O-rings to get rid of anything potentially nasty for your beer.

There are a few Corny keg washers on the market as well as DIY versions that make cleaning much more carefree, but there are a few key areas that require the most attention. Each time you clean your keg, you should take both posts off, take out the gas and liquid dip tubes, as well as the lid and the various gaskets and place them in a caustic or PBW solution and let the pieces soak. Scrub each piece with a brush as well as the threaded post stubs on your keg. The nice thing about Corny kegs is that you can fit your hand inside and clean out the underside of the top nicely. Once you have the inside of the keg and pieces cleaned up, rinse them all out to get all the cleaning solution off and reassemble the keg. 

During the cleaning process it is best to inspect gaskets for wear and replace pieces as needed. Most small post gaskets come in packs of 10 or more online while lid gaskets are usually sold individually. Before buying parts for your kegs, check the manufacturer to ensure you buy the correct pieces! Keg lube is always good to use to help when reassembling your kegs for sealing and gasket longevity — it is food-safe and won’t affect beer flavor or head retention. 

For sanitizing, my favorite technique is something similar to pro brewers. Add your sanitizer chemicals with proper dosing rate (I usually make about 1 gallon/4 L or less of solution), close up your keg and add up to 5 PSI to your keg. Shake, swirl, and move your keg to get the sanitizer in all those nooks and crannies. Once you’re positive it’s thoroughly sanitized, flip your keg upside down or at a downward angle over your knee. Open the relief valve for a few seconds to get the sanitizer solution inside of the components, then close it. Connect your gas connector, with no hose attached — you only want to get the sanitizer to go through the post and spring assembly. Disconnect the gas connector after about 15 seconds. Flip your keg right side up, connect 5 PSI of pressure to the gas side, and put a beer-out connector on your “out” post with a hose to a bucket. Connect your CO₂ and push all of your sanitizer out of the keg, then disconnect both connectors once it is fully drained. If you feel like there is any residue left, flip your keg upside down again and drain it through the relief valve. This method is ideal for pressure transfers but the lid can be removed (after depressurizing) for other types of racking. 

Alternatively, you can fill the keg with sanitizer, go through the shake routine, and then push the sanitizer from the keg with CO₂. Then, rack beer into the keg through the beer-out post so that there is essentially no air pick-up during racking, but make sure to relieve pressure build up occasionally. A brewer can also quickly open the lid after the evac cycle, dump in a priming sugar solution, close the lid, rack beer into the keg, attach a spunding valve, and keg condition. 

Carbonating Beer

Carbonation can be as easy or as complicated as you want it to be, like most aspects of brewing. When it comes to kegging, there are two ways of going about it. Naturally carbonate by adding priming sugar, let it sit at room temperature for about a week or two, and then you’re pretty much ready (the same way you would bottle condition). The second, more common, option is force carbonating, or adding CO₂ to your beer, letting it naturally dissolve into solution until you have the same effect. 

When it comes to naturally carbonating your beer, adding the proper amount of priming sugar and waiting is something you’re probably already used to if you’re coming from bottling. If you’re not, and going straight to kegs out of the gate, there are plenty of calculators to help determine how much priming sugar to add to get your carbonation correct. A spunding valve allows for the access of priming sugar to be added as well should you wish to add one. My one recommendation would be to pressurize your full keg just a couple PSI to get everything pressure sealed ahead of time. Some people incorporate a floating dip tube or cut off the last half inch of the liquid dip tube to prevent yeast from coming into the first couple glasses but that’s a personal preference. 

For force carbonating there are three options. The first one is using a CO₂ diffusion stone, which creates micro bubbles to help the CO₂ dissolve into solution fast. This method is used by pro brewers, but uses debatably more CO₂, and unless you have specialty equipment in the $1,200 range, it is going to be difficult to see exactly where your carbonation is at. The second and third are far more common — sometimes called the “Crank-N-Shake” and the “Set-N-Wait” methods. Both involve connecting your CO₂ to the keg and allowing for the CO₂ to dissolve into solution. Before diving into these techniques, carbonation must be understood.

Temperature and CO₂ solubility are directly related. The colder your beer, the more CO₂ your beer can retain in solution. As carbonation content increases for a given temperature, higher gas pressure is required to maintain equilibrium.  Since dispense pressure is tied to carbonation level, beers with lower carbonation levels require lower keg pressures. In this way we can look first at the “Set-N-Wait” method. If you Google “Beer volumes of CO₂ chart” you will find a slew of very colorful charts. These will show you temperature on one side and CO₂ PSI on another with a bunch of numbers in the middle. Those numbers in the middle are your volumes of CO₂. Most beers styles are served between 2.4–2.6. This number is the ratio of 1 L of CO₂ to 1 L of beer. Thankfully, most beers have a range of CO₂ volume you can easily find. For my beers, unless it’s a stout or a Belgian beer, I will go with 2.5 volumes. As an example: At 39 °F (4 °C), you will leave 12 PSI of CO₂ on your keg for a few days to a week to get it to approximately 2.5 volumes. One thing to take into account is altitude, in which you would need to add an additional 1 PSI per 2,000 feet above sea level. One thing that can affect carbonation is alcohol content, as high ABV will decrease carbonation — or more accurately, head retention. Regardless of if you use the Set-N-Wait method or not, understanding volumes of CO₂ and how temperature and pressure react to your beer is crucial in draught beer. 

Then comes Crank-N-Shake. For that you will first get your beer into the keg, add up to 5 PSI to counteract the temperature change, and put it in the fridge to the desired final serving temperature. Let it sit overnight to ensure the temperature is the same as your fridge, then hook up your CO₂ to it at about 20 PSI. Make sure your CO₂ tank is secure and start shaking the keg. You will hear the CO₂ hissing into the keg as it adds more and more CO₂ as some dissolves. Eventually the hissing will slow down until you can’t hear it anymore. This may take up to 10-15 minutes. Set it back in the fridge and wait up to 24 hours. Take a sample after it has settled and see where your carbonation level is at. Once it is at the amount you would like, refer back to the volumes of CO₂ chart to determine what pressure you should keep at it constantly. 

The Crank-N-Shake method has the same problem as force carbonating with a diffuser stone in that it is difficult to determine the carbonation level and it is easy to over carbonate, so in many cases people do a bit of both methods. Personally, I use both Crank-N-Shake and Sit-N-Wait for my 10-gallon (38-L) batches that are split between two 5-gallon (19-L) kegs. The first keg I want to hurry up and carbonate so I can start drinking it and the second keg I let gradually rise to the proper carbonation. 

In cases of over carbonation, you will want to relieve all the pressure from the keg until it has just enough to keep it sealed and dial back your PSI to 2–4. Slowly bring it up to determine your carbonation sweet spot when pouring. This can take some trial and error, so be prepared to possibly not get it right the first time, but don’t consider over carbonation in the keg a lost cause as there is always a fix!

Cleaning Your Lines

Cleaning your lines is the most important (and pretty much the only) maintenance you need to do once the beer is kegged and ready to serve. I first start with an initial cleaning and then clean the lines every two weeks from there. You want to make sure there is nothing in your lines to begin with and the maintenance cleaning every two weeks is to ensure you continue serving a good product by not having anything sticking to the walls of the lines. There are many line cleaning chemicals on the market but in general most are caustic-based. Read and follow all instructions in regards to preparing and handling chemicals first before using them. That said, there are many homebrewers who only clean their lines between kegs without issue, as long as they don’t sit on them too long.

I recommend always having one extra Corny keg for cleaning purposes alone. I first start out with about 2–3 gallons (8–11 L) of cleaning chemicals and put them in the extra keg with the proper amount of line cleaning chemicals. Make sure to wear gloves and eye protection as this stuff can pose a risk. Hook up the keg to pressure and allow it to pressurize to a few PSI. Once there is a bit of pressure, hook up the keg to the tap you are cleaning, ensuring the tap is not engaged! Grab a small bucket or pitcher and engage the tap. To prevent splashing you can put a towel over the faucet to bucket transition. Once the liquid looks clean, usually after a few seconds, disengage the faucet and dump out the “dirty” or tainted line cleaner. Once it is dumped out, start running the liquid again into the pitcher for about a gallon (4 L) and save the liquid.

Now you’ll want to turn off the faucet and disconnect your beer-out connection from the keg. While the beer-out connection is no longer attached, turn on the faucet to relieve any pressure, then turn off the faucet, and set aside the liquid. You now have the line full with the cleaning solution. Disassemble your faucet and let the pieces soak in your liquid you set aside. For this reason, I always recommend stainless steel faucets and assemblies as eventually any coated brass, although cheaper, will have the coating stripped from chemicals and beer and expose your beer to direct contact with the brass, potentially giving your beer a metallic flavor. After your pieces have soaked for 20 minutes, take a brush to them and clean off anything else stuck to them and rinse the line cleaning solution off. Clean off the beer shank a little bit before attaching and reassembling the faucet. Dump out the line cleaning solution from your keg and put about 2 gallons (8 L) of water into your cleaning keg. I usually do about double the amount of water that I did of cleaning solution. 

Pressurize and run the water through the line until it’s all gone. If you have pH paper or a pH meter use it to check that all of the caustic has been purged. Then, connect your line to your serving keg and run beer through for a few seconds to push out the rest of the water. Taste to confirm quality, and then taste again because you can! You can also use sanitizer such as Star San instead of water should you prefer. You can do the same process for acid line cleaning, but this only needs to be done when you start noticing beer stone and residual build up in the lines — but in all honesty, this is more recommended for commercial bars that move vastly more beer than you will. Should you feel like you need an acid wash, you might just want to replace the lines instead. 

Dispensing Beer

It’s not uncommon for your first pours to be either very flat or very overcarbonated. Flat tends to be not enough carbonation, which you can refer back to the carbonation section to fix. Too much foam on the other hand can be a few issues. 

One of the causes of foamy beer is dirty draught lines. Other factors that affect carbonation and foaming are gas pressure, temperature, tap height, serving line length and diameter. In most cases homebrewers beer taps are about the same height with lines that are roughly 3⁄16-inches and typically between 3–7 feet (1–2 m) long so the last few issues most likely won’t be a problem.  If you have longer lines or believe the taps are not balanced, refer to https://byo.com/article/balancing-your-draft-system

In most cases it is a matter of temperature. The most accurate way to tell beer temperature is to leave a thermometer in a bottle of water inside the kegerator for at least a few hours to get it acclimated. Once the temperature stays stagnant, you have an accurate reading. Temperature is by far the biggest problem, especially if the kegerator has an elevated tower. A tower blower is essential. Too warm, the more foam you will have.

If all seems to be correct so far, it might be possible your keg is overcarbonated and follow the steps laid out earlier to get it dialed in. 

Kegging isn’t for everyone, as plenty of homebrewers are happy to stick to bottles. But for many, it is a way of amplifying their homebrewing experience while making the tedious chores of cleaning easier. Once you get that beautiful nectar flowing, you’re all set!  

Written by Jadon Flores