Fever-Tree is a British producer of premium soft drinks , founded by Charles Rolls and Tim Warillow in 2004. The company's name comes from its initial product: tonic water. Their tonic was flavored with quinine, a chemical extracted from the bark of the South American cinchona tree. When first introduced to India as a pharmaceutical to help reduce fever associated with malaria, quinine was mixed with carbonated water and sugar to make it more palatable, producing the first tonic water. The cinchona tree was called in India "fever tree".
This soft drink is made with Tahitian limes from Mexico and yuzu from Japan. It goes well with vodka, tequila or mezcal.