A:AnswerSoda Stream is legally protecting themselves, because we are pressurizing a plastic bottle with their name on it. I have been using the same bottle for years. It's dated 5/2016 and I use it at least three times a week without issue.
Of course in my house food expiration dates are just a suggestion. We had a bottle of maple syrup in the refrigerator that had expired several years ago, until one day it was finally consumed. If it looks good, smells good, and tastes good . . . it's good. We're still alive.
A:AnswerI believe it's two years from when you put the bottle in use. But, like many foods, expiration dates are just advisory. I used my last Sodastream bottles for six years and recycled them only when they started to "fog", sort of like old car headlight lamps do.