Its first product was Premium Tonic Water, still Fever-Tree's flagship. It blazed the trail that led to the company becoming the world's leading supplier of premium mixers for alcoholic spirits.

That's why we tested and ranked 16 types of Fever-Tree mixers. The best of the bunch, the Elderflower Tonic Water, is not only the brand's top mixer, but it also makes for an excellent gin and tonic.

The cinchona tree is native to the Andean rainforest ... but you can also find diet tonic water that uses sugar-free ...