Seltzer Vs Club Soda Vs Tonic Water: Which Is Best For Your Cocktail
The classic first question you might hear at a nice restaurant: "Still or sparkling?" Would you like flat, normal water or fizzy water that's carbonated like soda? But is the glass of sparkling water the same as the club soda in the cocktails you order next? Not quite. It turns out, there are many different ways to make a glass of water start fizzing, and there are different ways to make the best use of each kind.
First off, seltzer is the most straightforward: It's plain water that's been artificially carbonated. While it's often drunk on its own, it can go into simple cocktails like a spritz. Club soda is a more common mixer, and it has some extra ingredients like mineral salts to give the carbonation a stronger "pop" that makes it appealing to mixologists. Tonic water is even more different: It's flavored with sugar and quinine (an old medication originally used to treat malaria as a healing "tonic"). That sugary, bitter taste can ruin some drinks, but it's a crucial part of other cocktails, like the classic gin and tonic (here's José Andrés' spin on the classic cocktail).
Understanding the fizz provided by seltzer, tonic water, and club soda
Since these don't sound like big differences, is it easy enough to substitute one for another while mixing a drink? Usually, it's no big deal to substitute club soda with seltzer, although your bartender probably won't. Club soda tastes saltier because of those added minerals — a common ingredient is sodium bicarbonate, aka baking soda. Salty tastes work wonders in cocktails, bringing out sweet flavors and tempering bitterness, so bartenders tend to prefer club soda over seltzer, though it's a small difference. If you substitute, make sure the seltzer is completely unflavored, because flavored seltzers like La Croix or Spindrift will change up your drink (although you could experiment with this too).
Tonic water makes for a poor substitute. The quinine it contains has such a bitter taste that the tonic water is frequently loaded with sweet-tasting sugar to balance it. The resulting flavor is complex, and it's frequently used in cocktails with few ingredients and a strong liquor like gin or vodka. Also, keep in mind that tonic water is the only option of the three that contains calories because of its sugar.
Make the most of your sparkling water
If you're looking for club sodas because of their extra fizziness, several popular ginger ale brands like Canada Dry, Schweppes, and Seagrams also sell club soda. There are fancier brands out there, but with club soda, flavor is secondary to its enhanced bubbliness. Your Tom Collins will taste just fine with any club soda because they'll all give your tongue a fizzy jolt.
There are a few other kinds of carbonated waters worth considering. Mineral water is similar but not the same as club soda. Brands like Perrier or San Pelligrino are bottled from natural springs and contain different minerals depending on where they're collected. When it's sparkling (it's not always carbonated), it can be seen as a pricier version of club soda, which makes it more appealing as a solo drink than a mixer.
Often, a distinction is even made between seltzer and sparkling water. The latter can be naturally carbonated while seltzer is always artificially carbonated. Not everybody makes this distinction, however, and seltzer and sparkling water are essentially the same when it comes to your mixed drink.