Vodka soda lovers enjoy the bitter bite that comes from the vodka. And if you like bitter, you'll like the vodka tonic. Kylie Barnett, a wine a spirits specialist, told me "If sweet isn't your thing, then a vodka tonic is the drink for you. While it has the same carbonated appeal of soda water, tonic water has a distinctly drier and slightly bitter taste due to the addition of quinine — an ingredient derived from the bark of the cinchona tree. If you're looking to switch up your vodka soda routine without getting too crazy, a vodka tonic is a refreshing alternative."