So fizz is entertaining, but it also serves a purpose. “Carbonated water lengthens and acidifies beverages,” says Camper English, author of Doctors and Distillers: The Remarkable Medicinal History of Beer, Wine, Spirits, and Cocktails. “In addition, the bubbles help lift aromatics from the drink and tickle your nose.”
However, not all carbonated water is created equal. “I know it’s strange to think about water as an ingredient, but it’s so important,” says Jena Ellenwood, cocktail educator at NYC bar Dear Irving. “The size and endurance of bubbles vary depending on the fizzy water.”
And it can make a difference when added to other elements in a drink, like spirits and citrus. In addition, some can add sweet, salty or bitter flavors, so it’s important to know which is which—here we offer this sparkling guide to the world of effervescent H2O.
A catch-all term for carbonated water.
Artificially carbonated water, with no minerals, added to it. This was the term mixologists used in the 1800s; they would have used glass siphons to create carbonation. Now, we have access to plenty of bottled seltzers, as well as home carbonating devices like the SodaStream and Aarke. Hard seltzer is a different animal; It’s brewed like beer with sugar and yeast, flavored, and then force-carbonated.
Best for: The Spritz
Artificially carbonated water to which sodium salts and/or potassium salts have been added. This is done to mimic the effect of bubbly mineral water, but the salts also are added to neutralize acidity in some water.
In terms of cocktails, seltzer and club soda are both relatively neutral, and can be used interchangeably, says Matt Chavez, bar manager of New York restaurant Ci Siamo. Think about them in terms of texture, not flavor: The bubbles may be larger compared to that of naturally carbonated mineral water and should “dance and tingle” on your tongue—it won’t change the flavor of a drink like a Tom Collins or whiskey highball, but can help “jolt it to life,” he adds. “It enhances the flavors in the cocktail, rather than bringing in more flavors,” Chavez notes, bringing a sense of freshness to a drink.
Best for: Tom Collins
Flat or sparkling water from a mineral spring. If it’s effervescent that’s naturally occurring, and the bubbles may be more delicate compared to seltzer or club soda. Most of these waters contain some degree of mineral content—hence the name— making them of great interest to early health practitioners.
“Naturally carbonated mineral spring water was thought to be extra healthy compared with regular mineral water, and far healthier than surface water from rivers and streams,” English notes. “European and American mineral springs rich in iron or other mineral salts were recommended to settle the stomach or treat conditions including anemia.”
Of note: Mineral salts can impart distinct salinity. Since the water is derived from a natural source, the flavor, saltiness, and bubbliness can vary widely. “Mineral water runs the gamut of flavor and carbonation—from super salty Vichy Catalan to mild, extra-fizzy Perrier, or a slight salinity and super fizz in a Topo Chico,” Ellenwood explains. “Personally, I like a hint of salt in cocktails, because it boosts other flavors— think salt in desserts.”
Best for Ranch Water
A sweetened soft drink made with carbonated water and quinine—the latter adds bitterness and was originally used as a medicinal tool to help ward off malaria. Tonic water is a key cocktail mixer (see gin and tonics, vodka tonics), and bartenders are clear: it is not interchangeable with seltzer or club soda since it adds perceptible bitterness and sweetness. Some brands add additional flavorings, too, like Fever-Tree Elderflower Tonic, which maximizes floral notes.
“Tonic is an acquired taste, and it is very far from neutral,” Ellenwood cautions. “Do not swap for anything else.”
Best for Gin & Tonic