
Soda water is plain water carbonated under pressure, with no sweetener or flavoring added.
Poured on top, it lengthens a drink and adds fizz and a light texture without changing the flavor. Add it last, after the spirits and syrups, so it keeps its bubbles.
Unflavored sparkling water
Does the same job, in the same amount, as long as it is cold and freshly opened. A strongly mineralized water makes the drink salty, so a lightly mineralized one is safer.
Tonic, lemon-lime soda and other sweet sodas
Not substitutes: they bring sugar and flavor and change the drink.
Still water
Will not do: it adds volume but no bubbles.
Keep it sealed and cold: a warm, shaken or opened bottle goes flat. Opened water cannot be re-carbonated, so buy bottle sizes that empty within one service.
Mojito (Cuban-style)
White rum