Seltzer vs. tonic water

What is the difference between seltzer and tonic water when making mixed drinks? Many never learn, mistakenly thinking they're the same. It's time to finally learn.

• Tonic water is normally used to mix drinks, and if you enjoy making cocktails, chances are you keep a bottle or two of tonic water in the house. But did you know that tonic water is infused with quinine? That's what gives it a slightly bitter taste.
• Believe it or not, quinine was an internationally recognized treatment for malaria, and was blended into tonic water to mask the taste of the substance. British soldiers stationed in India preferred drinking diluted quinine, and would mix other things into their tonic.
• Tonic water gained popularity in the 19th century, and was traditionally mixed with gin or another alcohol as well as sugar or citrus to improve the flavour. Most modern tonic water already contains sugar, and some have lemon or lime flavouring added. Commercial tonic water does not contain enough quinine to treat or prevent the symptoms of malaria.

• Seltzer or soda water is different from tonic water in taste because it contains sodium bicarbonate and potassium sulfate, which helps carbonate the water. Joseph Priestly created the recipe for seltzer or soda water in 1767. Seltzer did not become popular until the early 20th century, when it was fashionable to mix alcoholic drinks with it. Some people even had seltzer water syphons installed in their homes so that they could conveniently enjoy soda water at their leisure.
• Seltzer water and tonic water both made the consumption of alcohol more socially acceptable. Drinking liquor straight was not acceptable behaviour in public. However, infusing alcohol into either seltzer water or tonic water allowed people to consume less alcohol in a single drink and, therefore, drink more. Social drinking became commonplace once tonic water and seltzer water appeared.

• The difference between seltzer water and tonic water primarily lies in taste, which determines the types of alcohol each one complements best.
• Tonic water's slightly bitter flavour is very light and typically complements gin, although vodka also goes well with tonic water.
• The carbonation and strong taste of seltzer water is best mixed with stronger liquors that it will not overpower, such as Scotch.