How to Clean a Corney Keg

Do you clean your corney kegs?  If you are not completely dissembling them every time you are using them, you are leaving your self wide open to post fermentation infections.  There are more nooks and crannies in a corney keg then you may realize.  I recently cleaned  a corney keg the had whole leaf hop bits virtually clogging several inches of the dip tube.  Now had I not cleaned this, by the next time I used this corney, I would have had rotting bits of hops that would have infect my next batch.  While that is an extreme case, beer will dry up in the poppets leaving a sticky goo like residue, another place for bacteria to hide out and wait for your next batch of homebrew.

Here is a tutorial on how to clean your corney.  I recommend cleaning your corney’s right after you kick them.  It is the easiest while all the parts are still wet, basically will require less scrubbing of parts (assuming you started with clean parts).  Word of warning, if you’re mechanically challenged I would suggest taking pictures of how things looked before you take them apart.

Equipment Needed:

  • Socket wrench or Adjustable wrench
  • Carboy Brush
  • Tube Brush
  • Cleaner such as oxyclean
  • Hard tooth brush
  • Towels (I make a mess)

Wrench's Used to Loosen Stems

1) Release the pressure from the corney and open the top.  The tops are nearly impossible to open with the pressure.

2) Empty your corney and rinse with hot water.  This will give you base to start with.  If there is any caked on residue scrub it off with with your bottle brush or non abrasive sponge.

Corney lid, Pressure Release value, and lid's O-ring

3) With either a socket or adjustable wrench, you’ll want to unscrew the posts by turning counter clock wise.  The corney keg has 2 posts, a gas in and liquid out.  You will want to remove both. The corney’s have two possible posts a 12 point and 6 point (shown here) base.  If you have the 12 point you may have to get a socket that handles that or stick with the adjustable wrench.  If you are having a hard time loosening the posts, run them under hot water.  This will help loosen some of the gunk(yes the technical term) that may have acted as a glue.

Loosening the posts

4) With the posts off you should see a tube in each hole with a little rubber grommet.  With the c02 in, the little tube might come out with the stem.  The gas line in will be a much smaller dip tube, about 3 inches long.  Take the dip tube out, remove it from post if necessary.  Then remove the rubber grommet from the post.  The gas post is two pieces the stem with a poppet in the middle.  You should be able to push the poppet out of the stem by pushing on the little circle in the middle at the top of the stem.

Gas Line In, Stem w/ Poppet in, Grommet, and Plastic Dip Tube

Gas Line In, Stem w/ Poppet in, Grommet, and Plastic Dip Tube

5) Do the same thing you did for the gas in with the liquid out.  Gently remove the long dip tube.  It may be straight or bent as long as it goes to the bottom.  Roll off the rubber grommet and remove the poppet from the stem like you did before with the gas.

Liquid OUt, Stem w/ poppet in and Dip Tube with grommet still on

6) There is one more piece we can’t forget, the Pressure release value.  It is just as important.  On the lid, there is a value you used to release the pressure.  It unscrews.  Unscrew the value and put it with all the other parts.  While your at it, make sure the rubber o-ring has been removed from the lid, it needs to be cleaned.

At this point you have successfully disassembled your corney keg.  Now you are ready to clean.  THIS IS NOT SANITATION!  You are now ready to clean your the parts. I’m sure my methods very from others, but this has worked for me.

7) Check the corney for any residue on the walls, if there is any scrub away with carboy brush.  Fill corney with luke warm water.  When corney is filled with water add a scoop of Oxy Clean to corney.

8 ) Using the tube brush, run it through the dip tubes, both liquid (the long one) and the gas (short one).  This will loosen any gunk, then give it a rinse under some hot water to clear out any residual particles.  When done, put them into the corney with the Oxy Clean.

9) The grommets should be pretty easy to deal with.  Give them a quick once over with the tooth brush and toss into the corney with the oxy clean.

10) The stems and poppets could be more of a challenge depending on if or how long it has been since they were cleaned.  The stems are threaded, therefor have many more places for crap to build up. the poppets are basically springs and also have a lot of places for more crap to hide as well.  For these two pieces I use a hard bristle tooth brush.  if the goo doesn’t come off don’t worry, do what you can now and toss the poppet and stem into the corney.  You can give them another brush over when they come out of their Oxy bath.

Dirty Stem and Poppet

11)  For the pressure release value follow the same process as with the poppets and stem.

12) With everything soaking in Oxy, I usually let them sit over night.  You will see the Oxy Clean Bubble up and then retreat.  This is normal.

Oxy Clean doing it's work

These next steps are very important no matter what cleaner you use.

13) After the soak, drain the corney.  Since you have all sorts of small parts in the corney, I drain my through a pasta strainer.  You don’t want to lose any pieces, especially those tiny grommets.

14) With the Carboy Brush, scrub the inside and edges of the corney.  Rinse corney with hot water.  I usually rinse it 6-8 times.  I don’t want any Oxy residue left in the corney!

15) Run the Dip tubes under hot water.  make sure you rotate the tubes to ensure you are getting a complete rinse.

16) With the tooth brush, give each of the remaining piece a once over to ensure any crud is removed and then rinse well under hot water.

Corney Parts are Stored in Ziploc Bags

The Storage

At this point you are done CLEANING your corneys.  Since I have a ton of them, there are always some not in use.  For each corney, I take all the DRIED parts and put them in a zip lock bag, put the bag in the corney and cover the openings with tin foil.  All this will do is prevent any critters and dust from taking up residence in your keg.  The other reason I don’t reassemble the parts, I still need to sanitize the parts the next time I use it.  This way the parts are already disassembled for sanitation and I the less assembling and dissembling the longer they will last with out the extra ware and tear.

Corney Cleaned Ready for Storage

Before racking your beer to the corney and after sanitizing and re-assembling the parts, make sure you have good seals by doing a leak check with sanitizer.

I hope this How-To was beneficial.  If you have other techniques you use, I would love to hear them.  I’m all about improving my process!


7 Responses to “How to Clean a Corney Keg”

  1. Doug B. Says:

    Peter, you have been killing it lately with the great blog posts. Nice job!

    My method for cleaning my cornies is pretty close to yours. I also lube all the o-rings before assembly to encourage tighter seals. And I would like to point out to new corny owners that the post with the little horizontal notches on the star portion is the gas post and goes on the “in” side; very helpful when reassembling.

  2. Simply Beer Says:

    Thanks Doug, I’ve really be trying to incorporate much more homebrewing into Simply Beer, since that is where my real passion is. I’ll still be doing some reviews, but will be more sporadic. In Fact I i’ll be review all 3 of Southern Tier’s Cuvee Series in one shot.

    While I wasn’t really covering Assembling and Sanitation, that is a good thing to note regarding the lube. You want to have the best seals possible. I guess I’m going to have to do a follow up on assembling and sanitizing before racking. Thanks for making more work for me, Doug! :)

  3. Andy Z Says:

    Thanks for the post Peter! I follow a similar process, minus the toothbrush. Disassembling the pieces seems go a long way to keeping things clean, and soaking everything in OxiClean takes care of a lot of the work for you. My kegs have only been used once, so as I use them more and more, I’ll be sure to keep the tooth brush method in mind!

  4. Simply Beer Says:

    RIght on Andy. It’s amazing how much a little upfront work can save you on the brew & racking days.

  5. Jason Says:


    Good write up. However, I am much less diligent than you. ;)

    The turnover on my two kegs is quite high, so all I do is rinse, fill with Oxyclean, and leave overnight. I then purge the whole 3-5 gallon solution using CO2 to clean my tap lines. Rinse, and then sanitize. Only dissemble the popits every 5 batches.

    One important thing to note:

    Use Oxyclean free. The other brands contain chlorine.

  6. Eric Says:

    That really is a complete breakdown on how to clean a keg. I do it much the same way. But I agree with Jason, I don’t clean the popits every few times. Mostly just because I a nervous to lose the springs. Even though that should happen, it is a possibility. I have never used oxyclean before. How does it compare to StarSan? Its the only stuff i have really used.

  7. Simply Beer Says:

    Thanks Eric! On thing I forgot to mention in the post is to remove the poppet from connector. The pop out very easily with a phillips head screwdriver (try not to scratch the stainless). In the many years I have been doing this I have never lost any pieces since I strain the oxy going out through a large, thin mesh, colander. I have however mixed up posts and since there are several different types of corneys, you want to keep all the parts together. So even if I have to clean 3-4 corneys, I do them 1 at time and keep all the parts together in the corney they came from.

    I use Oxy or PBW to clean. Oxy free seems to get harder to find, so I’ve switch more to PBW. These are cleansers. Star-san is a no rinse sanitizer and requires scrubbing to remove any gunk. Oxy Free and PBW no scrubbing needed, just soak and rinse and the toughest crap will come off over night.

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