Fun with Carbonation Caps!

Carbonation caps are available in a number of styles and materials from various manufacturers. These are generally designed to thread into standard 1L and 2L PET bottles.

Sourcing a Carbonation Cap

FERRODAY Stainless Steel Carbonation Cap Forced Carbonation PET Bottle Filling 5/16 Barb CO2 Coupling to Carbonate Soda Beer Stainless Steel PET Bottle Carbonation Cap + O-ring + GasketWorks with both liquid and gas (double check current specs to confirm) – Ferroday Stainless Carbonation Cap Counter Pressure Bottle Filling With 5/16″ Barb – Hands on Review

Tee Fittings

These caps along with tee fittings have proven to be very flexible. Here are some application ideas…

PET Bottles as Growlers:

Fill up a 1L or 2L PET bottle with your favorite homebrew.  Put one of these on (purge the headspace by squeezing if you want to) and then pressurize for transport.  This should help to reduce oxygen pickup and maintain carbonation levels.

This article contains affiliate links. We may make a small percentage if you use our links to make a purchase. You won’t pay more and you’ll be supporting Homebrew Finds and more content like this. Thank you for your support!

Fine Tune or Rapidly Carbonate Homebrew:

Fine tune or rapidly carbonate beer. You can also use this cap to rapidly carbonate beer.  Same process as for transport, just set your regulator to the proper pressure and shake or agitate the PET bottle to help introduce CO2.  Or hook it up to CO2 and let it sit in you kegerator.

Draft Line Cleaning Projects

Clean kegerator lines are a key part of serving delicious beer. Bacteria and mineral build in lines can cause off flavors, quick loss of head, under-carbonated beer due to rapid co2 loss and lack of legs forming on the inside of your beer glass.

For these sorts of projects it’s important to source a carbonation cap that works with both LIQUID and GAS posts.

Convert a PET Bottle Into a Ball Lock Keg

You can use two carbonation caps along with a compatible tee and a length of tubing for a dip tube to convert a PET bottle into a ball lock keg.

Related: Hands on Review: Kegland Ball Lock Cleaning Kit

via William’s Brewing

via MoreBeer

Use a Carbonation Cap To Assist with Closed Transfer Racking

Thank you to Twitter Follower Josh @beardlywine for this tip!  Let’s be friends!  8 Ways to Connect with HBF – Thanks John!

Josh uses carbonator caps to assist with closed transfer racking to kegs.  If you look at the photo he shared, he’s putting a small length of tubing on the cap and then feeding that through the airlock grommet hole of his fermenter.  This same process could be adapted to work with other styles of fermenters.

Gelatin Fining in a Cold Crash Primary Fermentation Keg – Chino’s Gelatin Cannon

This process is from /u/chino_brews via r/homebrewing. Published here with permission. Thanks you Chino_Brews!

This is a method to fine your beer with gelatin in an vessel that contains a ball lock post (or pin lock post) without opening the vessel and introducing oxygen (air). A Chino Cannon (aka Chino’s Gelatin Cannon) injects the gelatin solution into the vessel through the post.

It can be used to inject many other things into a keg, for exampe (1) Star San into a keg that has been pre-purged by filling with water and pushing the water out with CO2, (2) tinctures, extracts, flavorings, or other liquid flavor additions, or (3) priming syrup being injected for natural keg conditioning/carbonation.


  1. Materials: (a) a barbed carbonator cap (see non-barbed variant) , (b) a small PET pop bottle with the same thread as a 2L Coca Cola bottle (PCO 1881 thread | Ø27 diameter 1881), such as a Dasani water bottle, (c) a short length of 5/16″ ID tubing that fits over the barb, (d) a jumper (see step 3), (e) a tool to vent the keg if it does not have a ring-pull pressure relief valve, and (f) gelatin solution. Ideally the type of carbonator cap that accepts a gas or liquid QD.
  2. Add Dip Tube to Carbonator: Add tubing to the barb so that when placed on the PET bottle it goes to a bottom “corner”. It is important to have the dip tube the correct length. You should cut a slight angle on the non-barb end of that tubing.
  3. Make a jumper: a jumper is a short length of tubing with a gas ball lock QD on one end and a QD that fits the carbonator cap for the other end. Connect the QDs with about 2-3 feet of tubing and whatever fittings you need (flare nuts, hose clamps, etc.) I strongly recommend using flare-type QDs for ease of cleaning, as mentioned below. VERIFY that the jumper is gas-tight and is not leaking.
  4. Fill Keg or other Vessel: Fill a pre-purged keg, give it just enough pressure to stay sealed after the temp drops, and then chill it. The beer can also be in another vessel that has a ball lock post, such as a conical fermentor or stainless steel brew bucket.
  5. Prepare Gelatin or other Injectable Solution: When the beer is chilled, heat some gelatin fining solution. When it gets to 130°F or less, pour it into the PET bottle, squeeze the air out, and cap it with the carbonator cap. MOVE QUICKLY from here on out. Note: PET melts around 140°F! The same process applies to priming sugar going into a keg. You do not need to heat other flavorings and can fill the bottle cold.
  6. Charge the Chino Cannon: Pressurize the PET bottle to a reasonably high pressure, 15-30 psi. Feel free to purge and fill as many cycles as your OCD about oxygen forces you to do.
  7. IMPORTANT: release the pressure on the keg.
  8. Connect the Jumper to the Chino Cannon: Hook up the jumper to the PET bottle. Hold the PET bottle upright so that the tubing inside is at the lowest level of the gelatin solution or other injectable. Now you have your Chino Cannon.
  9. Connect the Chino Cannon to the Keg or other Vessel Hold the PET bottle so that the dip tub is in the lowest “corner” of the PET bottle and hook the Chino Cannon’s gas QD to the keg. Watch the gelatin solution get rapidly shot into the keg! Feel free to rock the keg a bit to mix the gelatin with the beer if you want (not necessary IMO).
  10. Cleaning: remember that gelatin and other flavorings can literally be a nutrient for microbes. Furthermore, gelatin gels. It’s important to quickly disassemble and clean/rinse your Chino Cannon in HOT tap water while it’s still wet. It’s easy to clean now, but it will take more effort if you let the gelatin gel or sugars dry. This is where you’ll be happy if you used flare-type QDs so you can more easily get the residual liquid out with hot tap water. You’ll want to disassemble the QDs too.

More information: Photos, Video, a Non-Barbed Version and Troubleshooting Tips Chino Cannon (Chino’s Gelatin Cannon) via Reddit

Related: Five Benefits of Using Corny Kegs As Fermenters

Flush Keg Jumper Lines

This process is from /u/CascadesBrewer via r/homebrewing. Thanks you CascadesBrewer!

I have one connected to a short line of gas tubing and then to one of these disconnects. I can then hook that to my CO2 tank to flush CO2 through jumper lines, say when I transfer beer from one keg to another or the small jumper line I use to add gelatin into a keg.

Notes from HBF: With a universal carbonation cap (works with both gas and liquid QDs) you could use this same process to flush liquid jumpers with CO2.  Another gadget that helps with flushing lines is Valuebrew’s Ball Lock Jumper. That allows you to easily couple from QD to QD regardless of whether they are liquid or gas. That means you can easily flush liquid and gas lines with CO2.

Sourcing a Carbonation Cap

Tee Fittings

What Else?

Submit a Tip and Let us Know

Build a Simple Draft Line Flushing Setup

Keg Deals!

keg deals

Build a Recirculating Draft Line Cleaner

Rebuild Your Kegs!

Also Consider:

ball lock jumperStainless Steel Ball Lock Jumper with Food Grade Silicone O-Rings: Allows you to connect multiple ball lock runs to clean multiple lines and taps at the same time. Works with both liquid and gas QDs.  Stainless Steel Ball Lock Jumper – via Valuebrew – An easy add-on… food grade o-rings, featured in our Keg Rebuild Post

More Homebrew Finds!

Recent Deals!

Also: Kegerator Tips & Gear | Keg Repair Part #s | Recent Keg Finds

Our Top Draft Resources!

This post may contain affiliate links. We may make a commission when you use our links. This will never cost you extra. Thank you for supporting Homebrew Finds!

Price, promotions and availability can change quickly. Check the product page for current price, description and availability.

Make sure the components you use are compatible and rated for your intended application.  Contact manufacturer with questions about suitability or a specific application.  Always read and follow manufacturer directions. tag:lnksfxd toppost:funwcarbcaps tag:tpr

Leave a Reply