This article explains the differences between club soda, seltzer, sparkling, and tonic water.

However, there are many types of carbonated water available, leaving people to wonder what sets these varieties apart.

In fact, the sales of sparkling mineral water are projected to reach 6 billion USD per year by 2021 ( 1 ).

Simply put, club soda, seltzer, sparkling, and tonic water are different types of carbonated drinks.

However, they vary in processing methods and added compounds. This results in different mouthfeels or flavors, which is why some people prefer one type of carbonated water over another.

Club soda

Club soda is carbonated water that has been infused with added minerals. Water is carbonated by injecting carbon dioxide gas, or CO2.

Some minerals that are commonly added to club soda include:

potassium sulfate

sodium chloride

disodium phosphate

sodium bicarbonate

The amounts of minerals added to club soda depend on the brand or manufacturer. These minerals help enhance the flavor of club soda by giving it a slightly salty taste.

Seltzer

Like club soda, seltzer is water that has been carbonated. Given their similarities, seltzer can be used as a substitute for club soda as a cocktail mixer.

However, seltzer generally does not contain added minerals, which gives it a more “true” water taste, although this depends on the brand.

Seltzer originated in Germany, where naturally occurring carbonated water was bottled and sold. It was very popular, so European immigrants brought it to the United States.

Sparkling mineral water

Unlike club soda or seltzer, sparkling mineral water is naturally carbonated. Its bubbles come from a spring or well with naturally occurring carbonation.

Spring water contains a variety of minerals, such as sodium, magnesium, and calcium. However, the amounts vary based on the source from which the spring water was bottled.

According to the Food and Drug Administration (FDA), mineral water must contain at least 250 parts per million dissolved solids (minerals and trace elements) from the source from which it was bottled ( 2 ).

Interestingly, the mineral content of water may change the taste significantly. That’s why different brands of sparkling mineral water typically have their own unique taste.

Some producers further carbonate their products by adding carbon dioxide, making them even more bubbly.

Tonic water

Tonic water has the most unique taste of all four beverages.

Like club soda, it’s carbonated water that contains minerals. However, tonic water also contains quinine, a compound isolated from the bark of cinchona trees. Quinine is what gives tonic water a bitter taste ( 3 ).

Tonic water was historically used to prevent malaria in tropical areas in which the disease was prevalent. Back then, tonic water contained significantly higher amounts of quinine ( 3 ).

Today, quinine is only present in small amounts to give tonic water its bitter taste. Tonic water is also commonly sweetened with either high fructose corn syrup or sugar to improve taste (4).

This beverage is often used as a mixer for cocktails, especially those including gin or vodka.