Systems, methods and cartridges for carbonating a precursor liquid, such as water, to form a beverage. A carbon dioxide source can be provided in a cartridge which is used to generate carbon dioxide gas that is dissolved into the precursor liquid. A beverage medium, such as a powdered drink mix or liquid syrup, may be provided in the same, or a separate cartridge as the carbon dioxide source and mixed with the precursor liquid to form a beverage. The use of one or more cartridges for the carbon dioxide source and/or beverage medium may make for an easy to use and mess-free system for making carbonated beverages, e.g., in the consumer's home.