Here’s the big secret: both seltzer water and club soda are just carbonated water. That means they’re both plain water infused with carbon dioxide gas, which creates those lovely, tickly bubbles. But the difference? It comes down to a tiny, almost invisible addition.
Club soda has a pinch of minerals added to it, like potassium bicarbonate or sodium citrate. Seltzer water, on the other hand, is just carbonated water—pure and simple, with nothing else. That’s it. That’s the whole twist.
So why does that matter? Because those minerals give club soda a slightly smoother, more rounded taste, while seltzer can feel sharper and more neutral. It’s like the difference between a whisper and a tap on the shoulder.
