Soda And Tonic Water Aren't That Similar Aside From The Bubbles

If you put a glass of soda water next to one filled with tonic water, you would not be able to tell the difference. Both are clear carbonated liquids. But that's where the similarities end. Soda water has a neutral flavor, making it the perfect blank canvas for all sorts of beverages. Add syrup, and you have what many people call a soda or pop, while you can also add it to vodka for the popular fizzy cocktail known as the vodka soda, which is technically a highball cocktail. It's also one of the four ingredients used to make a popular lime-flavored Diwali drink of nimbu soda.

Tonic water, on the other hand, is markedly different. Even though tonic water starts with carbonated water, other ingredients in commercially-available versions of this beverage include sweeteners such as high fructose corn syrup, citric acid, and quinine. Quinine adds the distinct bitterness that we associate with tonic water, and without a significant amount of sweetener many would find tonic water to be almost undrinkable. With some sugar, however, tonic water lends both sweetness and a pleasantly bitter edge to drinks.

You may have only heard of tonic water being used to make a gin and tonic (pay attention to the type of gin you use here, by the way), but before that, one of tonic water's ingredients was a lifesaving discovery. The word tonic is usually used to describe a substance with medicinal properties, and that's exactly how tonic water started out. As early as the 17th century, people were using the bark of the cinchona tree to extract quinine, which was effective in treating deadly malaria. 

Soda water has a history all its own. Joseph Priestly, who learned how to trap carbon dioxide and add it to water to make it bubbly, added fizz to ordinary water back in the 18th century. He originally believed soda water could be used to cure another deadly illness of the era — scurvy — but that theory was disproven.

While we're at it, soda water shouldn't be confused with club soda. Soda water is a tasteless, bubbly water with some bicarbonate of soda added, but club soda has a lightly salty flavor due to the addition of minerals such as potassium sulfate and sodium chloride. One thing we know for sure is that they're all very different from tonic water.