Re: Where do they get the CO2 that makes soda fizz?

Good question! Carbon dioxide is produced everyday by plants and animals (yes, humans too) as part of their respiration process. But commercially, it is most economically efficient to purify CO2 from the by-products of other manufacturing process, like a fermentation (gas produced by bacteria as they grow) or of burning fuels (like in oil or gasoline processing). Companies like Praxair separate and purify carbon dioxide from these different sources for use in carbonated beverages and other foods.

I hope this info answers your question!

Kieran