What? half the calories!? It doesn't make sense, but this "Light" Tonic Water from Fever-Tree is just as delicious as their standard release, yet is only 40 calories per serving! This easygoing mixer is great in cocktails and mocktails alike. Fever-Tree explains their history: "Following a 'tonic tasting' in 2000 to find the best on the U.S. market, Charles Rolls—who built his reputation running Plymouth Gin—joined forces with luxury food marketer Tim Warrillow to analyze the composition of mixers. In 2004, they began creating mixers using natural and fresh ingredients. "Fever-Tree" refers to their first product launched to the UK, a Premium Indian Tonic Water, in early 2005. "Fever-Tree" is a colloquial name for the Cinchona Tree, where quinine, a key component for tonic, is found.