Ask Adam: Does Hard Seltzer Expire?

Absolutely! Most hard seltzer, with the exception of a few brands that are made by mixing actual seltzer with a spirit base, are made much the same way beer is: by brewing and fermenting sugar water (beer uses grain; in hard seltzer’s case, it is usually literally sugar). Once boiled, cooled, and fermented, this starchy water becomes an alcoholic base that is then flavored and carbonated.

As with any brewed beverage, there is a freshness window. If you drink outside that window, the seltzer will not taste as good. So if you have some White Claw left in the garage or basement fridge from last summer, better to buy a new case.