This page details my methods for using soda kegs (Cornelius, Firestone,
Spartanburg, etc.) for primary and secondary fermentation. Using kegs instead of
carboys or buckets is an easier way for me to complete the fermentation process.
Stainless steel also has many advantages over glass and plastic including being
unbreakable and oxygen impermeable. Cleaning and sanitizing kegs for
fermentation is no different than
cleaning a keg for serving. As always, it is important to have proper
sanitation techniques with everything that touches your beer.
Primary Fermenter
A 10-gallon ball-lock Spartanburg Challenger 'VI' keg is used as my primary fermenter.
These size kegs are rare but if you keep and eye out in online auctions or call
around to homebrew stores you will probably fine one. I purchased one in
great condition off eBay for $70 and it was well worth the price. The dip tube, and disconnect post
o-rings needed to be replaced but the poppets looked in good shape. The
lid o-ring was replaced with a slightly larger and softer o-ring available from
William's Brewing. They are ideal for fermenting because of the need
to seal the keg at low pressures.
The three-piece airlock is secured to the keg lid using a short 1.5" long
piece of 1/4" ID 1/2" OD vinyl tubing. Unscrew the pressure relief valve,
push in the piece of tubing, and fit the airlock into the other end of the
tubing to make an air tight seal. The bottom tip of the airlock, which has
an X shape, needs to be removed to allow for proper air flow.
I did not want to cut the keg dip tube in order to rack above the trub so I
could use it for serving in the future. Instead, a plastic racking cane
tip is used on the dip tub to help leave the trub behind. A racking cane
has a larger outer diameter than the dip tube so a 1/4" long piece of 5/16" ID
7/16" OD vinyl tubing helps in securing the racking tip. Cutting a small piece
out of the tubing to form a C shape makes the fitting easier.
Secondary Fermenter
My secondary fermenter is a 5-gallon ball-lock Cornelius keg. These
kegs are far more common than the 10-gallon size and can be purchased for less
than the price of a carboy.
All the o-rings on this keg were replaced including the
special lid o-ring for fermenting. The airlock was put in the pressure
relief valve hole in the same way as the primary fermenter described above.
I also did not cut the dip tube on this keg but used a plastic racking cane tip.
Racking
Using CO2 to push beer from the primary to secondary makes racking an easy
task. There is no need to move the primary fermenter and use gravity to
start a siphon, although this method could be used if you don't have a CO2 tank.
Since the fermenter is not moved, there is less chance of having sediment
stirred up into solution before racking. All I need to rack is two liquid
disconnects connected by a piece of 1/4" ID vinyl tubing and a CO2
tank with gas disconnect.
First, remove the airlock from the primary and
screw in the pressure relief valve. Connect the liquid out posts on both
kegs with the transfer tubing. Set the regulator to 0 psi and connect the
gas disconnect to the primary. Open the pressure relief valve on the
secondary or unscrew it and start pushing the beer with 2-3 psi. The
racking cane tip does a great job of keeping the trub in the primary and you a
have minimal amount sediment in the secondary. You may start picking up
sediment at the end of racking so stop the transfer by turning off the pressure
before this happens. Disconnect the gas and transfer tubing and secure the
airlock on the secondary.
Kegging
Transferring from the secondary fermenter to a keg for serving is the same
procedure described above for racking from primary to secondary. Since I
don't have a dedicated beer fridge in my small apartment, I only have two
2.5-gallon ball-lock Firestone kegs for serving. They fit nicely on the
top shelf of my fridge along with the 2.5-lb CO2 tank.
Bottling
Even though I use kegs throughout the fermenting process I still like to
bottle some of my batches in the end. Since I only have two small serving
kegs and like brew often,
bottling is necessary. Someday when I live in a larger house and have
a beer fridge I can keg everything, but for now I really don't mind the bottling process. A
bottling bucket is not used so the priming sugar solution is gently
stirred into the secondary. Then it sits for a while to allow some of the
yeast to settle before bottling.
You could use CO2 to push the beer into
the bottles but I simply raise the keg and use gravity because I'm waiting for
yeast to settle anyway. A bottle filler is connected to the out post of
the secondary with vinyl tubing and a quick disconnect. The siphon is
started by applying a small amount of pressure to the gas in post on the
secondary. The racking cane tip on the dip tube really does a nice job of
keeping yeast sediment in the fermenter without having to cut the dip tube.
