|Daniel's Soda-Water Machine|
I drink a lot of carbonated water. I enjoy the fiz and the bubbles bouncing off of my tongue. Don't judge me, it is the way that I am.
This is a practical DIY item, similar to my Homemade Geiger Counter from January 2010.
|Ambient air == no fun, squeeze it out!|
Fortunately a company in the U.S. makes just such an adapter. Search the web for Carbonator Cap PET and you should find any number of online suppliers willing to sell you one for anywhere between $12 and $20. The come in red or blue. You usually do not have a choice. I like the blue.
To use: Fill a PET bottle with dammed cold water. You can use kinda cold water, but you will fail at getting much fiz. You can take my word for it or Le Chateleir's Principal. "When a chemical system at equilibrium experiences a change in concentration, temperature, volume, or partial pressure the equilibrium shifts to counter the imposed change and a new equilibrium is established".
Remember in school when you asked your Physic's prof why you needed to learn this stuff and when would you ever need it? This is why and magically also the when. Water down at near freezing will absorb CO2 at the most successful rate. I caution that if using 0 degrees Celsius water that you use CO2 pressure at less PSI then warmer water levels since the PET bottle pressure will increase dramatically should that bottle be left on a room temp counter.
Carrying on.. squeeze the bottle to force out the ambient air mixture as nitrogen and oxygen will interfere with our process. Attach the PET bottle adapter and give the bottle one last squeeze as you press down on the valve on the adapter to 'burp' out any remaining air.
How much CO2 can be absorbed is limited by Henry's Law. That law states: "At a constant temp, the amount of a given gas that dissolves in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid". The more pressure, the more will be absorbed.
Continue to shake for 30 seconds.. rest for 30 shake.. for a couple of minutes. There is no set routine, really damn cold water will take on CO2 faster than cold and surface area is a factor. The nice thing about this set up is that I can deliver constant CO2 pressure to the solution whereas the air chuck guys need to keep topping up their bottles during the shake and dance phase. DO NOT allow your solution to flow up your line. That would be bad form as you would contaminate your line with your beverage. Not a huge deal when just carbonating water, but messy when you start to make your own fizzy lemonade or gin :)