How to store tonic water soda to retain its fizziness?

How do you keep tonic water fizzy?

Fizz is dissolved carbon dioxide, and it escapes when the bottle is opened, warmed or shaken. Everything below slows that loss.

Unopened bottles and cans

• Store in a pantry or cupboard at normal room temperature, away from sunlight and moisture. One beverage maker notes heat and humidity can dull flavor and fizz.
• Keep upright and still. Do not leave cases in a hot car or garage.
• The date on the label is a quality date. One maker says properly stored, unopened tonic can stay good for roughly nine months to a year past its date, but flavor and fizz fade, so use older stock first.
• Chill a bottle only when you plan to drink it. Cold storage is for convenience, not for extending shelf life.

After opening

1. Reseal the cap tightly right away.
2. Put it in the fridge; colder liquid holds gas better.
3. Pour gently and avoid shaking.
4. Drink it soon for the best fizz. Opened soda in general keeps some fizz about two to three days in the fridge.

Moving the rest of a large bottle into a smaller airtight bottle with less empty space can help, as can a reusable silicone lid for cans.

What not to do

• Do not freeze it. One maker notes freezing can cost fizz and change the flavor after thawing.
• Do not drink straight from the bottle if you plan to keep it. A maker advises tossing what is left about a week after opening if you drank straight from the bottle or can.

Signs to throw it out

• Completely flat with little flavor.
• A yellow tint in what should be a clear liquid.
• A dented, rusted, leaking or bulging can.

Flat tonic is not dangerous by itself. If you have some left, use it where fizz does not matter, or accept a quieter gin and tonic.