Or: Captain Mycroft and the Keg of Joy
Hello, friends—today, Mycroft the Old English Sheepdog and I bring you a tutorial on kegging, which takes a bit of extra equipment and practice compared to priming and bottling home brewed beverages, but is well worth the time, energy, and money in the long run, as:
- it carbonates faster, at 1-2 days vs. 2 weeks or more for bottle carbonation
- it allows you to dispense your beverage directly from the keg
- it doesn’t result in extra sediment in the finished beverage like traditional bottle fermentation does
Plus, if you’re a landlocked scuba diver like myself who is unable to dive much but looking to practice the skills you learned through all those diving certifications, kegging shares some similarities with diving in the equipment category, albeit with some key differences such as being unable to breathe the gas involved (well, you could try, but I wouldn’t recommend putting your lungs under 10 atmospheres of CO2 pressure with no oxygen…I really, really wouldn’t).
Finally, you can force-carbonate with a keg and then subsequently bottle the beer with a counter-pressure filler such as the Blichmann Beer Gun, so kegging can become a cleaner, faster first step toward eventual bottling as well—you’re not locked into serving from the keg.
I made a couple of common kegging mistakes while putting this tutorial together, which I’m excited to share with you as they should help you avoid or quickly fix these roadblocks when you start kegging.
The first step to kegging, assuming you have basic home brewing equipment already, is to buy a kegging kit or all the various individual components on their own. I recommend the kits, which are available—as are the basic home brewing kits which contain fermentation equipment–through Northern Brewer and More Beer. These kits will generally include some variation of the following components, along with accompanying instructions:
- A 5-gallon Cornelius-style soda keg
- A CO2 bottle filled with CO2
- A CO2 regulator
- Connectors and Hoses for connecting the regulator with the keg
You’ll also want to pick up a keg maintenance kit, which includes replacement rubber O-rings that will be needed at some point to replace existing ones in your keg. If you go with the Blichmann Beer Gun, you’ll need the accompanying accessory kit, which is needed in order to connect the beer gun into your existing kegging equipment.
Hint on kegs: The increasing popularity of 5-gallon soda kegs—particularly used kegs—has made it more difficult to find them—the online vendors are often out of stock—so if you are thinking about getting a keg and find that they are in stock on one of these sites through the above links, I’d recommend jumping on the opportunity quickly. One vendor that currently has a good supply of used kegs–like this one for instance–is Adventures in Homebrewing.
Other equipment involved in the process of kegging:
- A hydrometer, for measuring the residual fermentation content of your fermented beverage
- A test jar, used for containing the liquid your hydrometer will be floated in
- A kitchen scale, to measure out the sweetener used for back-sweetening (a common practice with cider and mead; not so common or necessary with beer)
- A wine thief–basically a giant, glorified plastic straw used to draw up a sample of liquid from a fermenter without disturbing the contents
- Potassium Sorbate, to stop fermentation when back-sweetening (otherwise, the yeast will awaken with a vengeance and produce additional carbon dioxide, which in a bottle could be disastrous and result in ‘bottle bombs’)
- A few gallons of sanitizer solution, made form a sanitizer such as Star San, plus a spray bottle filled with the same solution (for sanitizing small components and for checking for CO2 leaks in your kegging equipment
- A siphon assembly, consisting of an auto-siphon and appropriate tubing, for siphoning the contents of your fermenter into your keg
Keg, Regulator, CO2 bottle, mead (MEAD!!!), testing and sanitizing equipment.
This process assumes that your have already fermented your beverage—which will be the subject of future tutorials—and are now ready to keg and carbonate it. Alternately, if you don’t have hard cider, mead, or beer ready to keg, you could practice by carbonating water or making soda with one of the readily-available kits such as make-your-own-root-beer kits.
Here are the basic steps we’ll be covering:
- Testing the sugar content in your finished beverage with a hydrometer
- Adjusting the sugar content (if needed/desired)
- Transferring your beverage to a soda keg
- Attaching the regulator and various connections between CO2 bottle and keg
- Starting the carbonation
As you’ll find with most of my tutorials going forward, you start by sanitizing your equipment—in this case the keg—with sanitizer solution (typically a few ounces of sanitizer concentrate in a few gallons of water). I tend to use a plastic bottling bucket, plastic fermenter bucket, or a large metal stock pot for this—once I’ve sanitized my keg with it, I’ll return it to the bucket and simply soak my smaller components in that solution while doing my other prep work.
Your keg will come with cleaning instructions—such as this one from Northern Brewer—follow these, using the sanitizer solution you’ve just made.
For the auto-siphon, you can soak the hose and the siphon assembly but make sure to run some sanitizer solution through the inside of the tubing by starting a siphon of the sanitizer solution through it.
Through this process, you’ll get a ton of suds all over everything—this is harmless to your process, and you don’t need to try to clean out the bubbles from the keg or equipment; they don’t hurt anything. Save yourself some time and leave them.
Testing with a Hydrometer:
This simply involves taking a sample of your beverage from the fermenter with the wine thief, transferring it to the test jar (which looks like a large, plastic or glass test tube), floating the hydrometer in the test jar, and reading the sugar level from the markings on the Hydrometer.
First, a hint: Use water to test how much liquid the hydrometer displaces when placed in a test jar. This will help avoid messes when you drop a hydrometer into a completely full test jar and it spills everywhere. Use a sharpie to mark the level you need to fill to for the hydrometer to then raise the level close to, but not over, the top of the jar.
- To fill your test jar, place the sanitized wine thief into the liquid into the fermenter, give it a few seconds to fill up through the small hole in the bottom, place and hold your thumb over the hold in the grip, and extract the wine thief. Releasing your thumb releases the liquid—try to wait until you’ve positioned the thief above the test jar for this. Repeat as necessary to fill the test jar to the appropriate level determined by the hint above.
Is it really stealing if it was yours in the first place?
- Place the hydrometer about halfway into the liquid, spin it gently and release—it will float to a particular level and stop.
Hydrometer at 1.00
- Read the sugar level—most hydrometers will have color-coded ranges indicating common readings for finished beverages such as wine and beer. This reading is your final gravity reading. The liquid pictured above is a blackberry mead (a.k.a., a melomel), which finished very dry as indicated by it’s 1.00 reading, indicating no residual sugars
- To determine the alcohol content, use a calculator such as this one to determine alcohol by volume from original (pre-fermented) and final gravity readings
Adjusting Sugar Content:
This step is seldom needed with beer, which contains enough complex sugars that it usually doesn’t ferment out completely, but is very common for wine, mead, and cider, which consist mostly of simple sugars that yeast can very easily consume, assuming the correct conditions and nutrients are present. As a result, back-sweetening is often desirable to balance the astringency of a bone-dry beverage. With hard cider, it helps to balance the high acid levels that are naturally present.
Determine how sweet you want your beverage to be. This will determine how much sugar to add, if any.
- If you’ll be adding sugar, add Potassium Sorbate to your beverage (straight into the keg before transferring your beverage into it is fine) to prevent subsequent fermentation. You have live yeast in that beverage, so keep in mind that if you add sugar, they’ll restart fermentation inside whatever closed container you place it in. A keg can handle that—a glass bottle could explode.
- Determine how much sweetener to add, using an aid such as this one or with help from a good home brewing book such as my favorite, John Palmer’s How To Brew.
- Add sweetener by dissolving in hot water, cooling a bit, then adding to your fermenter. If your beverage is low in alcohol, you should probably boil the sugar(or honey) solution for a bit to ensure that it’s sterile—in my case the alcohol of the mead, at 12%, means it’s unlikely I’d have issues adding unsanitized sugar solution into the mix.
- Re-read your final gravity per steps 1-3 of the testing session above.
- Repeat as necessary to achieve the right balance
In the approach, err on the conservative side as if you sweeten too much, you can’t un-sweeten without diluting the solution, which dilutes the alcohol and flavors as well. A more precise method would be to sweeten a small, defined amount of the beverage to your exact taste preference, keeping track of the amount of sweetener, then extrapolating to the amount needed to bring the whole 5 gallon fermenter’s worth to that level. In my case I added a bit less than what I thought I’d want, tasted, and added a bit more and re-measured again.
Transferring Your Beverage:
Here, we simply transfer the beverage from the fermentation vessel into the sanitized keg.
- Place the sanitized siphon into the fermenter and the end of the tubing as far down into the keg as possible. It helps here to have the keg at a lower elevation than the fermenter, as it speeds the gravity-driven siphoning process and makes things easier to manage.
Fermenter on counter, keg on a chair at lower elevation.
- Start the siphon using the instructions that came with the siphoning kit—generally a pump or two on the siphon handle will get things going.
- Monitor the process, trying to avoid sucking the precipitated junk off the bottom of the fermenter into the siphon.
- Stop the siphoning—by lifting the siphon tube up above the level of the liquid—before the liquid reaches the bottom, so that you keep the precipitated materials in the fermenter and not in your beverage.
- Enclose the beverage by placing the keg lid back onto the keg.
Keg Lid; sanitizer bubbles visible on top of mead (this is ok)
Attaching the Pressurizing Equipment:
Here, we hook the CO2 bottle to the regulator and connect the hoses. Follow your equipment’s specific instructions; these are basic instructions and not all CO2 regulators are identical.
- Hook the pressure delivery hose to the valve on the regulator (the valve directly below the main assembly with the red shutoff switch, in my regulator’s case).
Regulator with connect hose attached at shutoff valve (red); with plastic washer.
- Attach the main regulator assembly to the CO2 bottle—making sure to place the plastic washer between the CO2 nozzle and the regulator to ensure a proper seal when you tighten the nut between the two. You’ll probably need a wrench to help you at this point, unless you were born in Asgard.
Mycroft! Fetch my wrench! Or drag it away and play with it…whatever.
- Connect the pressure hose to the keg. For ball lock kegs, this is pretty easy, you pull up the underside of the plastic connector, place the connector on the keg post, and release the underside. Hint: Do this with the red gas valve shutoff that the host connects into the regulator with turned off, so that you don’t blast air into the keg when you start to work with the pressure. This was my first of the errors I mentioned before. Not a big deal if the keg lid is already on at this point, as it was for me, but if it weren’t, you might get a bunch of sanitizer bubbles and CO2 to the face when you turn on the gas.
Starting the Carbonation:
Kegging achieves carbonation by forcing CO2 under pressure into the space between the liquid in the keg and the keg lid (this is called head space), which the liquid then absorbs. Carbonation is driven by a number of factors such as temperature and pressure; I don’t cover the science of it below, just the basic steps involved in kegging.
- Open the valve on the CO2 bottle a half turn. Check the gauges on the regulator:
- The bottle pressure gauge (on the left in the photo below) is a rough indicator of remaining CO2 in the bottle—in my experience and with my equipment, it tends to spike to 800 psi when connecting a full bottle, and will stay close to that value all the way until it drops into the red, indicating the need to refill the bottle soon…it does not go down gradually and does little to tell you anything except ‘plenty of gas here’ until it drops precipitously into the red. My thanks to ChillyCheese, a fellow redditor who provided a better explanation here.
- The delivery gauge (on top in the photo below) needs to be adjusted to your desired pressure—generally not more than about 15 psi and probably more like 10, by adjusting the screw on the face of the regulator (you’ll have to loosen the nut in order to drive the screw in further and increase the pressure). However, this can vary as well depending on the temperature you’re storing your keg in.
- Pull up on the release valve on the keg lid for a couple seconds to release the air in the head space and replace it with CO2 to better preserve your beverage.
- Listen for escaping gas from your kegging equipment—this is more difficult to discern the more burritos you consumed prior to kegging—aid this by spraying sanitizer solution onto the areas that could leak (connection points and the keg lid). Hint: Pay special attention to the keg lid, as if it’s seated just slightly wrong, it could easily leak. This was the second mistake, but luckily the sanitizer solution bubbled up visibly and alerted me to the source:
CO2 escaping from poorly-seated keg lid.
In addition, the tubing was improperly connected at the red shutoff valve, so I had to tighten that.
- Once there is no noticeable gas escaping, and the delivery gauge is at the proper place (see kegging instructions, but 10 psi is pretty typical), you wait. Hint: You can accelerate CO2 intake into the beverage by rocking the keg back and forth to agitate the liquid inside—when you do this, you’ll hear the regulator groan a bit as it delivers more CO2. Otherwise, wait for a couple days and check the beverage by connecting the serving tubing to the keg and dispensing some of it.
More specifics about carbonation can be found here; it’s an interesting topic that gets pretty in-depth.
From here, you can either serve the beverage straight from the keg or you can bottle using the Blichmann Beer Gun to deliver carbonated beer straight to the bottle. Once you have a kegging system, you’ll likely start looking for refrigeration equipment for it as well—kegerator time!–so consider yourself warned.
All in all it’s a great alternative to bottle fermentation and is a lot faster once you get the hang of it. You can also carbonate several kegs from one CO2 bottle and regulator with a few accessories, so it’s pretty scalable.
I hope you’ve found this tutorial to be helpful! I plan to create others on cider-making, mead-making, bottling, yeast, and sanitation as well, so look for more along these lines. Please use my affiliate links for Northern Brewer or More Beer if you’d like to pick up this or other home brewing equipment, as it helps me pay for upkeep on the site.
See the Resources page for more information about cider-making, cider makers, equipment suppliers, and more.
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Thanks for reading!