Making carbonated water is the process of dissolving carbon dioxide gas into potable (drinkable) water. There are two easy ways to carbonate your own water at home using dry ice and resealable plastic containers or CO2 cartridges and a seltzer bottle. Either way, you save money by carbonating your own beverages instead of buying sparkling water at a grocery.
How to Carbonate Water
Fill a seltzer bottle with water and attach a CO2 cartridge behind the nozzle.
Hold the bottle over a drinking glass or pitcher and press the lever on the seltzer bottle. The gas and water will combine instantly to carbonate your beverage under pressure into the glass or pitcher.
Use dry ice to carbonate water by placing 1 gallon of water in an airtight, resealable plastic container that will hold at least 2 gallons of fluid.
Add 1 pound of dry ice to the water and seal the container.
Place the container outside (to avoid a mess if the lid blows off) and wait approximately 1 hour for the dry ice to dissolve into carbon dioxide, carbonating your gallon of water.
Pour the carbonated water immediately into glass or plastic bottles fitted with airtight lids or screw-on caps.