Club soda is the middle child people often confuse with seltzer. It’s artificially carbonated like seltzer, but manufacturers add minerals (like potassium bicarbonate or sodium citrate) to mimic natural spring water’s taste. That’s why club soda has a slightly rounder, less sharp flavor.
Tonic water is a different beast entirely. It contains quinine, a bitter compound from cinchona bark, plus sugar or sweeteners. Tonic is a cocktail mixer, not a hydrator—think gin and tonic, not a mid-afternoon refresher.
Pro tip: If you’re mixing a cocktail, choose club soda for a subtle, neutral base. If you’re drinking it straight, go for sparkling water from a bottle with an Italian label. Your taste buds will thank you.
