At some point in our lives, just about everyone has wondered what exactly the difference is between seltzer and club soda. Seriously, aren’t they both just carbonated water? Well, wonder no more, friends, because we’re here to put your curiosity to rest.
Carbonated water of every stripe is just water that’s been pressurized with carbon dioxide. In its purest form, it’s called seltzer, or seltzer water, which is just water that’s been artificially carbonated with carbon dioxide. It has no other ingredients or fancy stuff; when you add bubbles to water at home in your SodaStream, you’re making seltzer.
As for club soda, it starts as seltzer, but during the manufacturing process a small amount of an alkaline mineral salt is added, usually sodium salt or potassium salt in the form of regular table salt or baking powder. If you check the nutrition label on a bottle of club soda, you’ll notice that there’s some sodium content; if you taste seltzer and club soda side by side, you’ll notice that there’s indeed a slight difference in flavor.
So why would salt be added to perfectly good seltzer? It all comes down to acidity. When carbon dioxide is pumped into water, the end result is slightly acidic. Alkaline salts help to neutralize that acidity, and the added minerals also make the taste resemble that of natural mineral water.
And as for “soda water,” well, your guess is as good as anyone else’s. Order it at a bar or restaurant and you’ll get a glass of carbonated water, but it might be either seltzer or club soda.