Tonic water is carbonated water with quinine, a bitter ingredient that was once used to treat malaria. Now, tonic water is mostly used to mix with alcohol, such as Gin and Tonic or Vodka Tonic cocktails.

Quick Answer

Tonic water does lose its taste and carbonation over time like most carbonated beverages. When left at room temperature and unopened, tonic water can last from 3-5 years. Once opened, tonic water will maintain its flavor for only 2-5 days. Tonic water will rapidly lose its carbonation and taste due to exposure to air.

If you have a bottle of tonic water in your cupboard or fridge and are curious about its shelf life, read on.

How Long Does Tonic Water Last?

Tonic water has Best-By dates that usually range to a year from the date of bottling. This is a manufacturer’s estimation of when tonic water will retain its quality. However, it can last much longer than that.

How Long Does Tonic Water Last Outside?

Unopened: Tonic water lasts up from 6-12 months from the “Best By” date when unopened and stored properly. Due to it being sealed, the air is kept out of the bottle, retaining its taste and carbonation for a long time. Tonic water will remain safe to drink long after the “Best By” date.

Opened: Tonic water only lasts a few days when opened and should not be left out. Opened bottles of tonic water will last 1-2 days before it starts to go flat and lose taste. While still safe to drink, the taste will be unpleasant and most people opt to throw it out.

How Long Does Tonic Water Last In The Fridge?

Unopened:  Tonic water will last 9-12 months past the Best By date if left in the fridge. Generally, tonic water lasts the same amount of time if kept in the fridge as if kept outside.

Opened: Placing tonic water in the fridge will keep tonic water fresh for 3-5 days. Its shelf life is short due to the contained carbon dioxide escaping and converting into air bubbles. The cold temperature will slow down this process but it will most likely go flat within the first 5 days.

How Long Does Tonic Water Last In The Freezer?

Tonic water will stay safe to drink for 9-12 months, the same amount of time if left in the fridge. However, it is not advisable to place sealed tonic water in the freezer. Freezing tonic water causes it to expand in the bottle and may cause the bottle to burst. Also, frozen tonic water will lose its carbonation and taste when thawed. The best place to store tonic water is in the fridge.

To sum up, tonic water can last a long time if unopened and placed in a dry, dark place. Once opened, its quality will quickly deteriorate and will lose its flavor and carbonation.

How Do You Tell If Tonic Water Has Gone Bad?

Taste: Tonic water has a naturally bitter taste due to the presence of quinine. When left out too long, tonic water will lose its CO2 and become flat. Take a sip of tonic water to check for taste. If it still tastes bitter, it’s fine to consume. If flat, you can opt to throw it out.

Discoloration: Tonic water is clear when fresh. Check the color for any yellow discoloration. Any sort of tint means the tonic water is old and should be tossed.

Smell: If the tonic water gives off any smell, it means the tonic water has gone flat and can be discarded. Most of the time, people will throw out tonic water if its taste is not optimal. Flat tonic water may not make you sick, but its taste may be unpleasant.

How Do You Store Tonic Water?

Unopened: The best way to store sealed tonic water is in a cool, dark place. Direct sunlight and oxygen will cause tonic water to lose its carbonation so as long as the bottle remains closed, tonic water will remain fresh and bubbly.

Opened: Placing opened bottles of tonic water in the fridge is the best way to keep it fresh and carbonated. Opening the bottle causes CO2 to release from the bottle so make sure the bottle is closed tight.

Can You Freeze Tonic Water?

You can certainly freeze tonic water so long as you allow some air between the mouth and the bottle. Water expands when frozen and a full bottle of tonic water may burst. Keep in mind that tonic water will lose its flavor and carbonation once thawed so it is not advised to freeze tonic water. Instead, opt to place sealed tonic water in a cupboard or the fridge if it’s already been opened.

Wrap Up

Now that you know how to store tonic water, you’ll know what to expect and how much tonic water to purchase for your next social. Gin and Tonic is a classic cocktail that many people enjoy. Remember to always check the Best By date and do a quick taste test to make sure the tonic is still enjoyable and won’t sour your drink.