- 1/4" O.D. plastic tubing (ice-maker tubing)
- a 1.5L soda bottle
- one or more 500 mL soda bottles
- an inline valve for 1/4" plastic tubing
- two 1/4" tube to 3/8" M adapters
- two 3/8" F couplers
- Teflon tape
- active dry yeast
Standard Disclaimer: Not liable for damages due to use or misuse. No warranties expressed or implied. For educational purposes only. Safety goggles may be required during use. Some belching may occur.
Step 1: Making the Connecting Tube
Assembly is pretty straightforward. Most of the connections are "quick-connect". No special tools required.
To attach the caps:
1. drill holes just large enough for the adapters
2. wrap the threads of the adapters with Teflon tape
3. use the couplers to tighten the adapter onto the cap
Note: I used brass couplers. I would've preferred plastic ones but couldn't find any.
Step 2: Brewing Some CO2
Close the valve on the connecting tube. Attach one end to the 1.5L bottle but don't fully tighten it yet.
Squeeze as much air as possible out of the bottle, then tighten the cap. This will ensure that most of the gas you end up with is CO2.
Wait. It'll take hours for the CO2 to build up to a decent pressure. The bottle will eventually expand and become firm.
Note: There's a chance that the connecting tube will leak or pop apart. If you leave the bottle too long, it could explode. Both of these are potentially very messy.