Process Lockdown Checklist: How to Prepare a Used Corny Keg

Link to the Tracker – Keg Tracking


Moving from bottling to kegging was a snap.  I wanted to go a different direction, and perhaps not spend as much time taking over the kitchen when my beer finally dropped bright.  It was taking way longer than I initially thought, and I was getting inconsistencies in the amount of carbonation from bottle to bottle.  I knew it was a mixing issue, but no matter what I tried, there were always a few that were almost flat, and a few of those that were gushers.  At 12 gallon batches, purchasing carbonation drops were too expensive to take seriously, and I was afraid of getting too much oxygen stirred in when I added the boiled sugar syrup.  I dropped a pretty obvious hint that I wanted kegs for Christmas (uhh, honey? Here is a link to what I want for Christmas, and let everyone else know too, ok?) and I sat back and let the holidays happen.


My wife Amber pulled through for me for Christmas.  She planned, ordered, cordinated and shared my keg desire, and by the time the holidays were over, I had recieved an assortment of kegs.  I had spent some time reading online about how they were going to save me a ton of time, and it was like only cleaning one bottle, and the mess would be reduced.  Boy, I was ready!  HAH!  The kegs ordered were old used Pin Lock coke kegs.  They were tested, and repaired if they didn’t hold pressure, but they were not cleaned.  Almost every keg I received for Christmas was a cherry cola keg save for one or two, which were sprite.  How do I know?  Well, all had syrup still in the bottom of them, but no fear!  Plenty of time spent cleaning them out and getting them prepared for use as a beer container.  I do think the reduced price of a used keg is worth it, as there is very little “work” that needs done.  PBW and sanitizer do the bulk of the heavy lifting, I only need to move the chemicals and rinse water around to ensure that they do their job and do a post cleaning inspection.  Sometimes a quick scrub is needed to hit the dry stuff.


Once I figured out what I had, I soon realized that some of the posts were not interchangeable with others, and the poppets were not shaped the same, and the dip tubes came bent or straight.  Some online study revealed there are more than one manufacturer of kegs out there, and I figured out that there are Firestone and Cornelius.  Firestone have the 9/16 sized post with an 18 thread count.  The Cornelius have a 19/32 post with an 18 thread count.  The Cornelius posts will fit on a firestone, but they will not seal correctly, nor will the poppets fit in the posts correctly.  The firestone posts will not fit onto a Cornelius keg.  The Firestone poppets seem to clip into the inside of the post, and will not come out without some effort.  I soon realized that I could not mix up the parts as it could spell disaster for a future brew.  This proved difficult as I clean more than one keg at a time.



As these kegs were new (to me) I did not have any of the hardware associated with kegging, like keg disconnects, a co2 tank, hose, or taps.  In my excitement to try out them, I thought that keg conditioning using sugar and dry hopping using pellet hops would be a worthy homebrew attempt.  The results were not stellar, and having learned from those mistakes, I purchased a few pieces.With plans to purchase more of these homebrew kegs in the future, I decided I needed a tracking system.  All the kegs are numbered, and logged in a spreadsheet.  After just a few kegs, it is easy to lose track of what beer is in what keg, when it was last disassembled, and if there were issues with it.  On the Spreadsheet I track a number of different items:


Initial acquisition date and Cleaning

Type (Cornelius or Firestone)

Date and type of fill (sparkling water, cleanser, sanitizer, beer + batch number)

Repairs/Replacements and Date (poppets, o-rings)


Keg Tracking



Procedure for cleaning:

When I purchase a used keg, I follow this cleaning & rebuild checklist prior to use:

  1. Remove stickers/Tape from exterior – scrub down
  2. Relieve the pressure.  Usually either pulling the relieve valve or by pressing on the gas side poppet.
  3. Open the lid – Rinse out –  fill with HOT water – add 2 Tablespoons PBW powder – Reattach lid
  4. Attach gas disconnect – Pressurize with 5-10 PSI
  5. Soak and agitate – shake keg, turn upside down.  Allow to Soak (1-2 hours)
  6. Attach disconnects – dispense 1-2 gallons through dip tube – remove
  7. add disconnect with short length of hose to gas
  8. Allow water to go out the gas line disconnect (turn keg on side)
  9. Remove Lid – dump rest of PBW water into bucket
  10. Remove O-ring from Lid and throw away
  11. Inspect interior for gunk –
  12. Unscrew disconnect posts – Remove and throw away O-rings from disconnects – Throw away poppets/springs
  13. Soak Posts and Lid in PBW
  14. Remove Dip tube and gas tube – remove O-rings and throw away
  15. Soak Tubes in PBW – Use dip tube brush
  16. Place Keg shell on Carboy Pump – Run additional PBW through open posts
  17. Scrub Small parts and tubes – Inspect for gunk
  18. Remove and inspect keg posts and interior for gunk –  rinse keg
  19. Rinse and Install new o-rings on tubes – place in respective threaded fittings
  20. Insert new poppets into posts, Install new o-rings into posts & Install into threaded fittings
  21. Rinse and Install new o-ring on lid – install into keg
  22. Pressure test keg – 25-50 PSI – spray all posts/fittings and lid with starsan or soapy water looking for bubbles
  23. Vent and repeat pressure test
  24. Set empty keg pressure to 15 PSI
  25. Dry exterior – Install Tracking numbers on side
  26. Record New keg data into spreadsheet.



If the keg is a new never been used before keg, the o-ring replacement and PBW soak isnt necessary, but a  scrub utilizing a surfactant to ensure any machining oils have been removed from the interior of the keg should be followed.  A quick rinse post scrub is required.  Attach the numbers for tracking purposes.


On the Spreadsheet, I have attached the link to my google drive.  You can go and see what I have kegged there!

Keg Tracking

4 thoughts on “Process Lockdown Checklist: How to Prepare a Used Corny Keg

  1. Great run-down. I have just started buying all the parts to start kegging; and have three second hand kegs. Here in Australia, the ball-lock is more popular, and I have three. Two are Firestone and one is a Cornelius. I went through them a week ago, replacing all the rubber parts (and lubricating them with keg lube) and scrubbing them within an inch of my life. Still want to give them another going over before I put anything in them. Love the write up; will bookmark and refer to it in the future 🙂

    1. Hi Jonno,

      Here the ball-lock are more popular as well, but I found a source that sell the Pin lock for cheaper than Ball lock. In addition, I like that I physically cannot connect them incorrectly, as there are 3 pins on the liquid out, but only 2 on the gas in.

      Thank you for taking the time to read it!

      1. For ball lock, I’ll just put a red o-ring on the gas in and a black o-ring on the liquid out. Much easier than trying to wrestle off the liquid out QD from the post from a confused moment. Plus the gas post has a ridge, or groove distinguishing it from the liquid post. Took me twenty years to realize that.

        1. I never thought about that, are the o-ring materials different? Like Viton for red, and Rubber for black? That is a great Idea, and I will implement as soon as I find some red ones. I am going to my Local Homebrew store this weekend, and will check it out!


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