Homemade Carb Caps (with pics)

You've heard of these before, but I figured I would post my build w detailed pics, so it's crystal clear.

So I stopped into Pep Boys and had a looksie around. They had the air chuck and barbs, but no chrome hex-nut tire stems. I didn't want the all rubber snap-in type. So I went to Napa Auto Parts, and they had 2 of them. Here's the purchase (except for the 4-way tool):



That hose repair kit was overkill, but for $3 I felt is was worth it. Now I've isolated the parts I'll be working with. The chuck + barb is for my CO2, then there's the valve stem as purchased, and the 4-way tool (which is used to help install the stem, and also to remove the valve for cleaning/sanitizing).



Next, I drilled a hole into the lid of a 23oz seltzer bottle (getting it center was an impossible task for me) using a 13/32" brad-point bit. Here's the mock-up of everything:

Next, I isolated just the parts which will be in contact with the beer or CO2.



These parts were cleaned w oxyclean free, and then sanitized in starsan. I sanitized the seltzer bottle w starsan, and put together the cap holding the valve stem with the 4-way tool threaded on. Next I drew off a sample of the bourbon barrel stout into the bottle, leaving about 1/6 headspace. Over the sink, I squeezed the bottle until a teeny bit of beer dribbled over (to displace all the headspace) then tightened the cap. Here's how she looks:



Then I put that in my keezer overnight to chill it. The next morning, I bled down a CO2 leg, and replaced the QD with my chuck setup (sanitized, of course):

With the regulator set at 15 psi (and the operator wearing safety glasses cuz I'm a wimp), I popped the bottle up to 15 lbs:



Then I shook the sheet outta that puppy until the beer absorbed all that gas. No problem.



Repeat that last step 2-3x until the beer won't drink anymore gas. And here it sits--waiting for the WHALES meeting. The other bottle is my dry chocolate stout that is ready to be kegged but I wanted to taste w bubbles.



'assit, kids.

SUMMARY

Here's the parts list with prices:



notes:

- Unless you're comfortable using pliers on the valve stem (which I wasn't), it's almost impossible to get that sucker tight enough before first use. HOWEVER, once you pop to 15 psi the first time, you can then tighten up that hex nut with no problems cause the pressure holds the assembly tightly in place.
- I would have bought 4 tire valves, but Napa only had 2 on the shelf.
- Obviously, the chuck, barb, and 4-way tool are a one-time set up purchase.
- The actual cost of the carb cap is $3.19 plus whatever you paid for the bottle and cap (.40 ea at A&P for plain seltzer).
- I discovered that the rubber ring used on the inside of the stem's flange is about the same size as a keg post o-ring. I might try and get a good seal on that with water in the bottle after today.

special thanks to bobby_m for the direction to go here.

Personally I would have gotten a clip-on air chuck, that way you could carbonate by doing the old "set it and forget it".

Just my 2 cents.

M_C

Misplaced_Canuck said:

Personally I would have gotten a clip-on air chuck, that way you could carbonate by doing the old "set it and forget it".

Click to expand...

Excellent point, Canuck. And I was just chatting with a friend that I AM going to get one for just that purpose. But I was on a time crunch with the meeting looming, and this made do. Thanks!

This is very cool!

And I agree, the clip-on would be awesome and convenient.

We chatted about this already, but don't be a wimp with the pressures. Soda bottles can take a lot of pressure, no problem.

The clip on chuck is nice, but this also isn't an assembly I'd leave sitting gas overnight. If it leaks, your tank is done.

The easiest way to handle unassisted, but predicable carbonation is to just eyeball the headspace to total volume ratio and inject that many times the pressure into the headspace. Leave it overnight, or shake, either way and you hit the correct volumes.

Here's the easy example: 2 liter bottle filled with 1 liter of beer. You know your fridge is about 38F and you want 2.5 volumes, the chart says 11psi. The headspace to total volume ratio is 1:2 so you set your reg to 22psi and give it one shot until the gas stops flowing (3 seconds).

2.5 volumes fixed... shake it a bit to speed things up or leave it in the fridge an hour.

It gets a little more tricky when the ratio is 1:6. It just means you need to put 66PSI on it. I know, it's getting a little scary at that pressure because it sounds high, but the bottles can handle it. Store bought soda is carbed to about 3.5 volumes so when it's in the delivery truck at 90F, it's hitting 61psi. However, anything that needs more than 50psi, I'd probably just keep hitting it with pressure and shaking.