What Is Tonic Water? A Bitter Explainer

Have you ever ordered a delicious Gin and Tonic, taken a sip, and wondered, “What is tonic, anyway?” Good for you for questioning the things you ingest—albeit a little late. It’s a valid question. What is tonic water, exactly? Is tonic and seltzer water the same? Does tonic water have sugar? How much sugar is in tonic water? And what is quinine in tonic water? Don’t worry, we’ll answer all your questions so you can stop questioning your choices and feel good about taking that next sip. 

What is tonic water? 

Tonic water is a bitter, carbonated soft drink made with quinine and some sort of sweetener. It’s often used as a mixer. What does all that mean? The main difference between tonic water and other carbonated water drinks is its bitterness. Why is it like that? What’s in tonic water to make it taste that way? That element comes from quinine. 

What is quinine in tonic water?

Quinine is a medication that is used to treat malaria and comes from the bark of a cinchona tree, which Native people in Peru and throughout Central America used to treat ailments. The Jesuits brought this antimalarial medication from Central America to Spain and it spread across Europe. Quinine helped keep Europeans malaria-free and sent colonialism and the slave trade into hyperdrive as Cinchona trees were introduced to Indonesia, Java, the Carribbean, and Africa. 

In British-controlled India, the British East India Company popularized a drink of quinine, carbonated water, sugar, and lime—aka tonic water. 

So, what is Indian tonic water? 

Jacob Schweppe created and sold Indian Tonic Water as a “prophylactic against the killer disease.” And so tonic water was born as “Indian tonic water,” a disease killing soda water in Colonial India.

Does tonic water have sugar?

Tonic water is a combination of carbonated soda water with dissolved quinine and sugar. You read correctly; even though it’s called “water,” the answer to the question, “Does tonic water have sugar?” is one big yes. 

How much sugar is in tonic water? 

An average serving of tonic water has 32 grams of sugar. Tonic water also often contains citric acid (or some sort of citrus flavoring) and preservatives. 

Does tonic water have alcohol?

While tonic water is often used as a cocktail mixer, plain old tonic water does not contain any alcohol. 

Is club soda the same as tonic water? 

Nope. Club soda is carbonated water that has minerals added, usually potassium sulfate, sodium chloride, disodium phosphate, or sodium bicarbonate. These give it a slightly salty taste. Tonic water is made with carbonated water, quinine, usually some kind of citrus flavoring, and sugar or some other kind of sweetener to offset the bitterness of the quinine. 

Is tonic and seltzer water the same thing?

Nope, tonic water and seltzer water are different things. Seltzer water is simply water with carbonation added to it. There is carbonated water in tonic water—but there’s also sugar and quinine. 

What does tonic water taste like? 

Fizzy, bitter, a little lime zesty, and a little sweet. It’s a very specific flavor that’s really unlike any other fizzy beverage out there. 

What is tonic water good for? 

Tonic water is good for mixing drinks—primarily Gin and Tonics or other clear spirits and tonic such as white rum or mezcal. These days, there’s not enough quinine in the mix to actually protect against malaria, so don’t try and replace malaria pills with a few Gin and Tonics on your next safari vacation. That said, some people say it helps them calm their restless leg syndrome. But, really, you should just stick to using it to make delicious G&Ts or sipping it solo on a plane, the only place where it’s acceptable to order straight tonic water. 

Does tonic water go bad?

It is possible for tonic water to go bad. Tonic water comes with a best buy date. If your tonic water changes to a darker color or loses its carbonation, it’s probably gone bad. Don’t hang out with bad tonic water. It’s a bad influence. I did five years in a state penitentiary because I ran with some bad tonic water for a while.