Not all SodaStream gas cylinders are the same. In fact, there are three different types of gas cylinders that can be used with a SodaStream machine - CO2, Nitrogen, and Carbon Dioxide/Nitrogen mix. The type of gas cylinder you use will depend on the type of SodaStream machine you have. Here's a breakdown of the different types of gas cylinders and which machines they're compatible with:
CO2: Compatible with all SodaStream machines. This is the most common type of gas cylinder used with SodaStreams. CO2 is what carbonates your water and gives it that fizzy feeling.
Nitrogen: Only compatible with the Sodastream Jet machine. Nitrogen is used to pressurize the water in Sodastream Jet machines and give it a smoother texture when carbonating. It doesn't actually add any flavor to your water though!
Carbon Dioxide/Nitrogen Mix: Only compatible with Sodastream Source machines. This mix provides both carbonation and nitrogen pressurization in one gas cylinder - making it super convenient if you have a Sodastream Source machine.