Filling and Serving From a Keg
tl;dr: This post is an introduction to using kegs for beer as an alternative to bottling.
After your beer is fermented, packaging it for consumption is the next logical step. I watched a friend bottle 5 gallons of beer and thought “not for me”: From my very first batch, I used a keg. With a keg, there’s only one container to clean and sanitize, one transfer from the fermenter, and the beer is precisely carbonated overnight. Even though it costs a bit more to get started, what you save in time and effort, plus gains in convenience, make it worthwhile.
Kegging isn’t for everyone. If you give a lot of your beer away, bottles are much more convenient. Some don’t have a place to refrigerate a keg (although some kegs are pretty small). Or maybe your 1 gallon batches are just a little too small to justify getting a full keg system. It’s not a trivial investment: Between a used keg, gas and liquid fittings, some hose and a tap*, as well as a CO2 tank and regulator, we’re looking at about $250. (*A plastic ‘picnic’ tap is about $10, as opposed to a stainless-steel Perlick for $100).
First, have a look at the blog post “Anatomy of a Corny Keg” at <
https://www.brewersfriend.com/2009/08/15/anatomy-of-a-keg/>. That will show you what kegs and their parts look like.
Then, just note that there are few keg manufacturers, and their parts can differ somewhat, important when buying replacements. The kegs we use come in 3, 5 and 10 gallon sizes – we’re not discussing ¼ or ½ barrel commercial kegs here.
Next, have a look at the blog post “Keg Care and Cleaning – PBW vs Oxyclean” <
https://www.brewersfriend.com/2009/08/29/keg-care-and-cleaning-pbw-vs-oxiclean/>. Clean kegs are just as important as clean bottles, but there are more parts to a keg.
Once you have a clean and leak-free keg, you are ready for packaging. Sanitize the inside of the keg, and all hoses and fittings, for example using StarSan. Drain the keg, install and close the lid and, as you tighten the bail (the wire handle that closes the lif) , wiggle it so it finds its happy place. If the lid if a little off center, it can leak. Continue to flip the bail until the lid is sealed. Connect CO2 to the keg and purge the oxygen. Some introduce the CO2 using the liquid out port, keeping the heavier-than-air CO2 at the bottom and purging the air from bottom to top. Others just pump CO2 into the gas port, using the pressure release valve ring to vent the air. I purge the air before I seal the lid, using the CO2 tank like a garden hose for about a half minute. Just get most of the oxygen out, however you choose.
The filling process is reasonable simple, whether you gravity-transfer or pressure transfer: The basic process is to drain the fermenter into the keg, at least until the keg is full. To do this, prepare a hose with fittings that go from the fermenter spigot to the liquid-out port. Then connect a blank (no hose) gas fitting to the gas-in port, to allow pressure to escape. Open the spigot, verify liquid is flowing, and wait. If your fermenter has more than 5 gallons, the keg is full when liquid starts coming out of the (blank) gas port fitting. If \you have less than 5 gallons, the keg is full when you run out of beer in the fermenter. Try to avoid getting the last dregs from the fermenter, the beer in the keg shouldn’t have any trub or other spoo in it – it can clog the valves. Once full, remove the keg fittings, as you are done.
Carbonating
Carbonating is a simple process. Connect the CO2 tank’s output to the keg’s Gas-in port and add pressure. How much pressure depends on the beer’s temperature and how much carbonation you want. Some beer styles (like a porter) call for light carbonation, while others (Hefeweitzen) call for a lot of fizz. Use a carbonation chart (there are many, all essentially the same) to determine how many PSI of CO2 is needed for the beer style at the serving temperature, set the regulator and leave it sit for a few days at serving temperature with pressure applied. It carbonates itself.
A faster way is to start at around 40 PSI, and with this high pressure applied, rock the keg several times. You will hear CO2 flowing through the regulator – this means the gas is dissolving into the liquid (which is the goal). Let it sit overnight at this high pressure as you chill the beer to serving temperature. The next day (12 hours or so at least), reduce the pressure to what the carbonation chart says and leave it another half day, but samples at this point are encouraged.
Time to Drink!
Lastly, reduce the pressure to serving pressure and dispense a half cup and throw it away. This ensures anything that isn’t beer – you had sanitizer in that beer tap and hose, didn’t you? – is flushed out of the system. If you dispense at carbonation pressure, it’ll probably be all foam. So, what’s serving pressure?
Serving Pressure
An IPA at 40 F might need 18 PSI carbonation pressure. A party tap with a 6-foot 1/4” (6 mm) ID hose might want 8 PSI serving pressure (you should test this and figure out a good pressure on your own). So, either turn your regulator down to 8 PSI for the duration of the party, or close off the regulator and pull the ring on the pressure release valve until much of the pressure escapes. Pour a beer (or a few), the open the regulator and re-pressurize the beer for storage. Leaving it at serving pressure will let it go flat.
Some add more hose, or use thinner hose, to their tap so they can serve at carbonation pressure. Each diameter hose needs a certain amount of pressure to ‘overcome’, so about 20 feet of 1/4” hose might dispense perfectly well at 18 PSI. The resistance of typical serving hoses (inside diameter) per foot are as follows:
5/16 (8 mm) – 0.4 PSI
1/4 (6 mm) – 0.75 PSI
3/16 (5 mm) – 2.0 PSI
Another alternative is to cool the beer further. 18 PSI at 40F is the same as 14 PSI at 33 F (about 3.03 “volumes” of CO2). Or drink less fizzy beer perhaps.
Kegs are just so much more convenient than bottles. After the keg is empty you can let it sit for several days, pressurized, before getting around to it*. Of course, you can clean and sanitize it immediately as well. I will take a keg, clean it and put in a half-gallon or StarSan. I purge the oxygen, then pressurize the keg to about 10 PSI. I give the keg a good shake, and put it in storage. It only needs to be depressurized** and drained before it is ready to be filled.
*I have several kegs, so getting one ready for the next batch isn’t usually a priority.
**The pressure i\s to prove to myself that it holds pressure. If a ‘ready’ keg doesn’t have pressure, I need to find the leak be3fore moving forward.
Finally, although many have covered this topic, note that John J. Palmer, in his book
How to Brew, covers the kegging process comprehensively and is a worthwhile read.
I did give it a good clean but I’m guessing it wasn’t enough. Now I primed my beer in the keg and gased it too 30 psi which is what I was told but when I came to set it all up too the tap there was no gas left. So I’m guessing air had got in and sent my beer sour. Plus it went in lovely and clear came out very cloudy. Can anyone help? Should I not have aged my beer in the keg with the priming sugar? 
