I can't believe that I haven't mentioned this little offshoot of the Project yet! Part of the reason I was able to get into kegging my beer was the premise that we could make our own soda at home...just as good, if not better than one of the long-running appliances can.
All you need is a CO2 tank, a regulator, gas-out hose and a ball lock gas quick disconnect, and a Carbonator Cap to get started. The Cap is basically a hard plastic "gas in" post that threads on to a PET bottle (Pepsi brands and most store brand bottles work, but the new thin Coke ones do not!) that used to hold a carbonated beverage. Don't try to re-use a plastic water bottle, it WILL explode!
Fill a bottle to about 3/4 capacity of COLD water. I fill my bottles and let them sit in the fridge overnight, and this is done because CO2 is more easily absorbed into cold liquid. Take your Carbonator Cap and once it is threaded on, simply depress the (we'll call it a) button in the middle while squeezing the bottle to force out any oxygen. You will know it is all out once the water squirts out the top a bit.
Then attach the gas disconnect to the Cap, and turn the CO2 regulator on and set to about 40psi. Shake the bottle like you are mad at it for about 30 seconds (a little more or a little less depending on bottle size and your desired CO2 level). Then turn off the CO2, remove the gas disconnect, then slooooooowly remove the Carbonator Cap. The reason you need to go slow is to vent out a bit of the gas so the water doesn't gush out at you! Then quickly cap the bottle with its regular cap, and you have just created sparkling water! Congrats!
At this point, the sparkling water mixes nicely with juice, as well as pre-made soda extracts. The SS brand of extracts is actually quite good, and we have used them exclusively for our soda making needs. To add them you would pre-measure out the amount of extract needed for the bottle size you are using, then slowly pour it into the already carbonated bottle. If you just dump it in (I did my first time making soda) it will turn into Old Faithful and gush out all over the place. SO SLOW POURING IS KEY!!! Then screw on the cap, invert the bottle a few times to mix, and enjoy your homemade soda!
Why not just purchase the SS appliance to do all this? Good question, and one I researched a bit. The up front cost for my rig was definitely higher, but the savings are in the gas. The SS CO2 bottles are about $15 each and can carbonate 60 liters at the lowest setting. to get the same "store bought" carb level, you have to at least double the amount, therefore only getting about 30 or so liters from each. My standard 5 pound CO2 tank costs about $12 to refill, and it lasted well over a year and a half, and hundred(s) of liters before it needed to be refilled. I honestly lost count it has been so long.
Just wanted to share this with you guys out there that might be looking for another reason to get into kegging, or simply to stop having to lug around soda from the store!