Homebrew Kegging Setup, Step by Step

Before anything

Sort the CO2 and the seals

Two tasks that have nothing to do with beer and that stop most first setups dead.

The cylinder arrives empty. Almost universally. Find a local gas supplier, welding shop or fire extinguisher service that fills or exchanges CO2, and do it before your beer is ready rather than on the evening you want to keg.

Replace every seal on a used keg. Reconditioned cornies are excellent value and they come out of commercial service with old rubber. Replace the lid gasket, both post O-rings and both dip tube O-rings -- a complete seal kit is inexpensive and fitting one prevents a week of hunting a leak that is quietly emptying your cylinder.

Step 1

Clean and sanitize the keg properly

1. Dismantle it. Lid off, both posts unscrewed, both dip tubes out. Flushing a closed keg is not cleaning it.
2. Soak the components in a warm non-caustic alkaline brewery wash. Pay attention to the post bodies and the inside of the dip tubes, which is where soil hides.
3. Scrub the keg interior -- stainless tolerates a brush -- rinse thoroughly, then reassemble with the new seals.
4. Sanitize. Fill with a couple of liters of no-rinse sanitizer, seal, shake it around to wet the whole interior, then push the sanitizer out through the liquid post with CO2. That sanitizes the keg and the dip tube and leaves the keg full of CO2 -- which is also step 3 done for free.

Step 2

Leak test before the beer, not after

This is the step people skip and regret. Pressurize the assembled keg to around 20 psi, then:

• Spray soapy water or sanitizer on the lid seam, both posts, the disconnects, and every line fitting. Look for growing bubbles.
• Close the cylinder valve and leave it overnight. If the regulator output gauge has dropped by morning, you have a leak downstream.
• Most leaks are the lid gasket or a post O-ring. A smear of food-grade keg lube on the lid gasket helps it seat.

Step 3

Purge the keg, then transfer

Oxygen is the main thing that will degrade your beer in the keg. If you pushed sanitizer out with CO2 in step 1, the keg is already full of CO2 and you are done. Otherwise, pressurize and vent several times -- less complete, but far better than transferring into an air-filled keg.

Then transfer. If your fermenter is pressure rated, do a closed transfer liquid post to liquid post and the beer never meets air at all -- see how to pressure ferment. If not, siphon gently with the tubing outlet below the beer surface in the keg to minimize splashing, then seal and purge the headspace once more.

Step 4

Set temperature first, then pressure

The order matters and nearly everyone gets it backwards. CO2 solubility depends on temperature, so a pressure only means something at a stated temperature. Chill the keg to serving temperature first -- around 38°F -- and let it get there fully. Then set the pressure that delivers your target carbonation at that temperature.

For most ales at 38°F that is roughly 10 to 12 psi. The full reasoning and the numbers for other styles and temperatures are in CO2 regulator settings, and if you want carbonation in days rather than a week, how to force carbonate.

Step 5

Balance the line, or accept foam

The last piece, and the one that explains most “it pours all foam” complaints that are not a temperature problem. Beverage line has flow resistance, and the job of the line is to drop the keg’s pressure down to roughly zero at the faucet. Too short a line and beer arrives at the faucet still under pressure, where it breaks out of solution as foam.

Practically: if you are serving at 10 to 12 psi through standard 3/16 inch beverage line, you want several feet of it -- considerably more than the short length many kits ship. If your pour foams at a correct temperature and pressure, add line before changing anything else.