For most of my homebrewing career I’ve relied on just two methods for packaging: bottle conditioning and force carbonation in a keg. Once in awhile I'll naturally condition in the keg, but that is only if I have a beer ready to keg and no open slot in my kegerator to put it. When I had a batch on tap that I wanted to enter into a competition or bring to a homebrew club meeting, I really only had one option, stick the bottle under the tap and deal with some overflow and then cap.
While this most basic bottling option is alright for short term transportation, it has the tendency to allow oxygen from the air to dissolve into the beer, and to knock carbonation out of the beer. In both cases the result is beer in the bottle that will not be as delicious as it was on tap. When Zymurgy posts the winning recipes each year from NHC, it is amazing how many people force carbonate and then bottle from the keg (19 of the 24 winners in 2012). Over the last couple years this has been not just IPAs and light lagers, but also sour beers, imperial stouts, and English ales as well. Of course this is a correlation, and not causation (it could be that brewers who are more serious about brewing for competitions also happen to want the precision of force carbonation).
Luckily there are a number of gadgets available to improve the transfer of carbonated beer from the keg into the bottle. To bottle test batches for samplings at public tastings (sign up for the Modern Times email newsletter), and meetings with investors/distributors, we first opted for the Blichmann BeerGun, and more recently the Fermentap Counter-Pressure filler. After trying both, I thought I'd write down my thoughts on where each excels, and what to consider if you want to start bottling from the keg.
Ease of use
Fermentap Counter-Pressure: With a counter-pressure filler the bottle is flushed and then pressurized with carbon dioxide before filling. The pressure prevents the beer from foaming much as it is transferred into the bottle. However, when the bottle is full and the stopper is released the beer will begin to gush. This is fine as it allows you to cap on foam, but you have to be quick. I’ve found it really helps to have a second person to take the filler to shorten the time between removal and capping.
The Fermentap's three-way ball valve is a bit more cumbersome to operate than the BeerGun's button/trigger. It is easy to allow gas or beer to continue flowing slowly if you aren’t careful when turning it to the off position. This filler also causes more of a mess, beer spurts through the valve when it reaches the top, and the previously mentioned gushing means that filling bottles placed in a large bowl/pot/bin is a must.
Blichmann BeerGun: Solid and relatively easy to clean. My only real complaint is that the small rubber nub on the tip of mine fell off and was lost. An email to Blichmann resulted in me being told that it wasn’t covered by the warranty, and that I needed to order another ($4.50) nub from a homebrewing store. The BeerGun seems easier to sanitize than the Counter-Pressure, without as many internal parts where microbes can hide.
Fermentap Counter-Pressure: The first filler I received leaked from the stem, and second one leaks from the valve (CO2 pressure, and then beer vent even when the valve fully closed). It is a bit disappointing that the product isn’t tested before it is sold. Luckily the slow leak is enough that the product still works alright, but the loss of the ability to throttle the flow is annoying.
Fermentap Counter-Pressure: The beer can be bottled at a higher pressure without excessive foaming, and being able to dispense at serving pressure seems to have resulted in more consistent results. The flavor is similarly good to the BeerGun, no complaints over the short term (you can read my tasting notes for my Aromatic Cream Ale both on tap and in counter-pressure-filled bottles in this post).
The fillers cost about the same, Blichmann BeerGun is $75 while the Counter-Pressure retails for $65 for the standard or $87 for the “Deluxe” model with a pressure gauge. The price goes up if you need to buy beer/gas line and extra fittings. Luckily I have a spare barb on my gas distributor, so I can sanitize it and dispense CO2 without putting a splitter on the gas each time I want to bottle.
Tips and Tricks
Whichever one of these you decide to purchase, there are a few tricks that make them more effective:
Dispense into cold/wet bottles to minimize foaming. I sanitize with Star-San, then put the bottles into the freezer for 15-20 minutes. When I am ready to fill I give each a last blast with Star San to ensure they are still wet and sanitized.
Chill your beer close to freezing, to minimize the amount of CO2 lost. I usually leave my kegerator set to around 40-45 F, but a day before bottling, I crank it down into the mid-30s F.
For the BeerGun, you need to turn down the head pressure to ~4 PSI to slow the speed at which the beer dispenses. For the Counter-Pressure filler, leave it set to the same pressure as the keg because the pressure will slow the speed at which the bottles fill.
A long/narrow liquid line helps, once again, to add resistance which helps minimize foaming and loss of carbonation. This is much more important for the BeerGun.
When using the Counter-Pressure filler, hold the stopper in firmly while it is under pressure, but don't push down on the filler itself. Especially for larger bottles, you don't want the stopper to ride-up and lose its seal around the stem.
The effort of setting up either of these is only justified when you are filling multiple bottles, or packaging a couple beers. When I’m headed to a homebrewing club meeting I still usually just stick a chilled/wet bottle or growler under the tap.