Homemade Carbonator Caps, contributed by flaminio Options

[cj in j]

Homemade Carbonator Caps FAQ
contributed by flaminio

Carbonator Caps are the lazy way to bottle your beer from a keg for near-future drinking. Just pour your beer from the tap into a 2-liter soda bottle, twist on a Carbonator Cap, squeeze out the head space, then tighten. Finally give it blast of CO2 and you're good to go. This is also a handy way to force carbonate a small volume of beer using the shaking method. The only disadvantage is once you open the bottle, it's best to drink the 2-liter in one sitting. Did I say that was a disadvantage?

However, while Carbonator Caps are great, they can also be expensive. I often take homebrew with me when visiting friends and family to leave behind, and I also send bottles home with guests. At around $10 a pop, they are expensive to have out on extended loan. And compared to DIY, they're also just plain old expensive. So, let's look at how to make your own Carbonator Caps.

Homemade Carbonator Caps
The idea is to take the cap from a 2-liter (or any other) plastic soda bottle, drill a hole and stick a tire stem in there. Then you use an air chuck connected to your CO2 tank to pressurize the bottle. I found a 31/64" drill bit to fit nice and tight. I use a pair of pliers and pull the stem through the cap. A 1/2" bit will work too -- I've used both but find 31/64" the smallest you can get away with, making the tightest fit. You may want to step up the hole with a smaller bit to make things easier. Make sure you drill near the center or else it could be tricky to get the cap on the bottle. Wear work gloves or a vice to get a hold of the cap while drilling.

On the CO2 side, you'll need a barbed swivel nut on your CO2 line. This will give you a 1/4" female end. Then you take the flared end of a flare-to-pipe fitting and connect that to the nut and the other end to the air chuck.

With the tire stems, a lot of people seem to like the chrome versions, but I found these hard to find. Talking with others, specifically Thom Cannell who wrote an article on these for BYO, the rubber ones are fine. I just went down to the neighborhood tire place, and they gave me a handful of them. I soaked them in a concentrated Star-San solution and rinsed. There's no rubber smell and nothing can be detected in the stored beer. So, use what you like, but the rubber ones seem to be a practical solution.

One advantage of making your own caps is that for the same price as one Carbonator Cap, including the one-time fittings, you can make up a bunch of homemade caps. Also, Carbonator Caps are designed for 2-Liter bottles. If desired, you can make your own custom caps for 20 oz bottles, or any other size plastic soda bottle.

Here's what a finished cap looks like.


Parts List and Sources
Air Chuck -- $2 (Lowes #3626 / 104ZN-RET)
1/4" x 1/4" Flare-to-Male Pipe Half Union (Lowes: #WATTS PB48)
Barbed Swivel Nut 5/16" barb to 1/4" FFL -- $3.25 (LHBS)
Tire Stem Valve -- $1 (Belle Tire)
2-Liter Soda Bottles & Caps

[DavidS]

Here is a pict of my parts.

(IMG:http://i245.photobucket.com/albums/gg60/dsegletes/img_0805.jpg)