For those that keg their homebrew, there will always come a time when you would like to either share or save off some of your wonderful elixir in a couple bottles. This is made easy and possible with a tool called a beer gun.
A beer gun is an attachment that hooks up to your keg and CO2 tank and dispenses beer directly into your bottles. These beer guns fill bottles quickly, easily, without the risk of oxygenation and without complicated counter pressure filling equipment. Beer guns come with two triggers: one that will purge the bottle of oxygen and the other that will dispense the beer.
Using a beer gun can be a bit tricky for those trying it the first time. Here are some tricks I’ve learned throughout the years.
Be prepared to waste a lot of beer when you first start. I must have wasted loads before I got everything dialed in.
Firstly, get everything ready before you start. Get your bottle caps and capping tool all within immediate reach. This is always forgotten by those starting out because they are just so damn excited to start using the beer gun.
Pour yourself a glass of beer using the beer gun first. This will allow you to get the hang of using it as well as remove 100% of the oxygen from the line. The most common problem with the first pour is excessive foaming, and with a glass you can just let the foam subside and drink it later.
Make sure your bottles, sanitizer liquid and beer gun are cold. Aim for the same temperature as your beer, this will help avoid foaming. Put them all in your kegerator or fridge to ensure the temps are as similar as can be. Colder is OK as well, so a quick 10 minutes in the freezer is great for those that forgot this step at first.
Dispense the beer with really low pressure, around 2-5 PSI. This low pressure will prevent the beer spraying that happens at high speed. High pressure will also make the beer foam like crazy. If you try to dispense with a beer gun at regular serving pressure you will regret it. Don’t forget to purge the keg of pressure after changing the pressure setting.
Bottle over a bucket or pan to catch any beer that foams over. Until you get the hang of the tool, you are probably going to make a mess.
Use a pitcher of sanitizer to hold the gun while you cap. My process is to do a 5 second CO2 purge of the bottle, fill, another quick headspace purge, then set the cap while storing the beer gun in the pitcher. I then crimp the cap immediately. (I don’t try to do multiple bottles at once.)
Bottle right after filling your keg. If you know you are going to fill a couple bottles to save for later, you should fill them immediately after your keg has been filled and its headspace purged. This will give you the best results with minimal foaming or waste.
Fill a growler instead. If you plan on opening the bottles soon, or are simply giving some beer to a friend, consider using a growler instead. Just hook up a sanitized silicon tube and fill the growler until its 100% full. This beer won’t last as long as your bottle will, but usually it doesn’t have to if its being shared.